$28 Find Cheap Flights to Waterloo

This is the cheapest one-way flight price found by a KAYAK user in the last 72 hours by searching for a flight to Waterloo departing on 1/10. Fares are subject to change and may not be available on all flights or dates of travel. Click the price to replicate the search for this deal.
1 adult
1 adult, Economy, 0 bags

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Everything you should know

Cheapest round-trip
$100
Overall average: $179
Frontier
Tue 1/27Wed 1/28
DEN - STL • 1 stop
Cheapest non-stop
$103
Typical prices: $78-$310
Frontier
Fri 1/9Mon 1/12
DEN - STL • Non-stop
Top routes
DEN-STL
Cheapest
BOS-STL
Most popular
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Flight Deals
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Flight Deals

Cheap Flights to Waterloo

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights to Waterloo that are departing in the next months. While these flights were available on KAYAK in the last 72 hours, prices and availability are subject to change and deals may expire.
Discover the best prices for you by selecting your travel dates on KAYAK.

Recent round-trip flight deals to Waterloo

Tue, Jan 27 - Wed, Jan 28
Frontier Logo
7:30 am - 6:51 am
DEN
-
STL
22h 21m1 stop
Frontier Logo
3:46 pm - 5:23 pm
STL
-
DEN
2h 37mnonstop
$100Frontier
Fri, Jan 9 - Mon, Jan 12
Frontier Logo
6:50 am - 10:02 am
DEN
-
STL
2h 12mnonstop
Frontier Logo
7:43 pm - 9:15 pm
STL
-
DEN
2h 32mnonstop
$103Frontier
Thu, Feb 19 - Sat, Feb 21
United Airlines Logo
8:40 am - 10:13 am
IAD
-
STL
2h 33mnonstop
United Airlines Logo
8:30 am - 11:40 am
STL
-
IAD
2h 10mnonstop
$265United Airlines
Thu, Jan 15 - Sun, Jan 18
United Airlines Logo
5:38 pm - 11:59 pm
IAD
-
STL
7h 21m1 stop
United Airlines Logo
8:30 am - 11:40 am
STL
-
IAD
2h 10mnonstop
$271United Airlines
Wed, Jan 14 - Wed, Jan 21
Southwest Logo
2:35 pm - 4:30 pm
HOU
-
STL
1h 55mnonstop
Southwest Logo
6:00 am - 8:20 am
STL
-
HOU
2h 20mnonstop
$273Southwest
Tue, Jan 27 - Thu, Jan 29
Delta Logo
6:30 am - 8:34 am
LGA
-
STL
3h 04mnonstop
Delta Logo
6:00 am - 2:44 pm
STL
-
LGA
7h 44m1 stop
$277Delta
Wed, Jan 14 - Wed, Jan 21
American Airlines Logo
9:00 am - 6:14 pm
JFK
-
STL
10h 14m1 stop
American Airlines Logo
6:00 am - 11:39 am
STL
-
JFK
4h 39m1 stop
$280American Airlines
Thu, Jan 15 - Sun, Jan 18
Delta Logo
6:00 am - 9:39 am
IAD
-
STL
4h 39m1 stop
Delta Logo
6:00 am - 11:37 am
STL
-
IAD
4h 37m1 stop
$281Delta
Wed, Jan 14 - Wed, Jan 21
Southwest Logo
11:20 am - 5:05 pm
HOU
-
STL
5h 45m1 stop
Southwest Logo
6:00 am - 8:20 am
STL
-
HOU
2h 20mnonstop
$283Southwest
Fri, Feb 20 - Wed, Feb 25
American Airlines Logo
5:09 pm - 9:41 pm
LGA
-
STL
5h 32m1 stop
American Airlines Logo
6:00 am - 11:22 am
STL
-
LGA
4h 22m1 stop
$287American Airlines
Useful Info

Good to know - Book Cheap Waterloo Plane Tickets

Low seasonJanuary
Cheapest flight$28
Best time to beat the crowds with an average 7% drop in price.
Most popular time to fly with an average 3% increase in price.
Flight from Denver to St. Louis

Flights to Waterloo: the best tips from KAYAK users' own experiences

Insights shared by verified travelers who flew to Waterloo 
Verified travelerFlew with Alaska Airlines
SEA
-
STL
Jul 2025
Give yourself extra time. Love the self check in options.
LarryFlew with Southwest
LAX
-
STL
Apr 2024
For long flights on airlines built for short flights (SWA) anyone over 5’ 10” is going to get cramped. Consider an Economy Plus upgrade when available.
Verified travelerFlew with Alaska Airlines
SEA
-
STL
Feb 2024
Be sure to measure your wheels for carry on my luggage was the correct size but the wheels made it over so had to check my bag wasn't happy about that since you have to pay for checked should at least get one free.

FAQs - booking Waterloo flights

  • How long is the flight to Waterloo?

    Flights from New York2h 43m
    Flights from Denver2h 21m
    Flights from Boston2h 59m
    Flights from Atlanta1h 46m
    Flights from Orlando2h 33m
  • What is the cheapest flight to St. Louis?

    In the last 3 days, the cheapest flight deal to St. Louis was found on the route from Denver, at $100 return. The most popular connection is from Boston to St. Louis and KAYAK users have found round-trip deals for as low as $328 in the last 3 days.

  • Which airlines fly to St. Louis?

    Many airlines fly to St. Louis, the most common ones being Southwest, American Airlines, and Delta. See the amount of flights per week for popular airlines flying to St. Louis.

  • How to fly to Waterloo?

    You cannot fly directly to Waterloo. KAYAK recommends you fly to Lambert-St Louis (STL) (31.07 miles from Waterloo). From there you can rent a car or get a taxi.

  • What airports are near Waterloo?

    The closest airport is Lambert-St Louis (STL) (31.07 mi). Other nearby airports are Marion Williamson County (MWA) (73.86 mi) or Cape Girardeau (CGI) (82.94 mi). KAYAK recommends you fly to Lambert-St Louis.

  • How far is Lambert-St Louis Airport from central St. Louis?

    The city center of St. Louis is 13 miles from Lambert-St Louis Airport.

  • What is the name of St. Louis’s airport?

    There is only 1 airport in St. Louis, called Lambert-St Louis Airport (STL). It can also be referred to as Lambert Field, Lambert-St Louis, St. Louis Lambert, or St. Louis Lambert Intl.

  • How does KAYAK find such low prices on flights to Waterloo?

    KAYAK is a travel search engine. That means we look across the web to find the best prices we can find for our users. With over 2 billion flight queries processed yearly, we are able to display a variety of prices and options on flights to Waterloo.

  • How does KAYAK's flight Price Forecast tool help me choose the right time to buy my flight ticket to Waterloo?

    KAYAK’s flight Price Forecast tool uses historical data to determine whether the price for a flight to Waterloo is likely to change within 7 days, so travelers know whether to wait or book now.

  • What is the Hacker Fare option on flights to Waterloo?

    Hacker Fares allow you to combine one-way tickets in order to save you money over a traditional round-trip ticket. You could then fly to Waterloo with an airline and back with another airline.

  • What is KAYAK's "flexible dates" feature and why should I care when looking for a flight to Waterloo?

    Sometimes travel dates aren't set in stone. If your preferred travel dates have some wiggle room, flexible dates will show you all the options when flying to Waterloo up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Top tips for finding cheap flights to Waterloo

  • There is no major airport in Waterloo. It is instead served by Lambert-St Louis Airport.
  • Looking for cheap airfare to Waterloo? 25% of our users found round-trip tickets to Waterloo for the following prices or less: From Miami $253, from Boston $282, from Los Angeles $292
  • Enter your preferred departure airport and travel dates into the search form above to unlock the latest Waterloo flight deals.

Reviews of the top 5 airlines flying to Waterloo

 
Need help choosing which airline to fly with from the United States to Waterloo? KAYAK airline reviews give an overall score for each airline based on loads of factors, including comfort, boarding, in-flight entertainment and more, to make your decision easier. See airline scores according to verified KAYAK customer reviews.
7.9
SouthwestOverall score based on 4252 reviews
8.6Crew
8.0Comfort
8.1Boarding
7.5Entertainment
7.0Food
Airline reviews

They sent a notice that they were boarding an hour early. We had to leave the club and run to the gate. They said sorry, that came from corporate and was a mistake. They did not have enough seating because the flight before it had not taken off on time. They moved our gate and delayed it for an hour.

2.0 MediocreRobert, Dec 2025
LAS - TPA
Read more Southwest reviews

They sent a notice that they were boarding an hour early. We had to leave the club and run to the gate. They said sorry, that came from corporate and was a mistake. They did not have enough seating because the flight before it had not taken off on time. They moved our gate and delayed it for an hour.

The boarding and seat assignment system no longer works for me, but I know it is being replaced. Otherwise, I am good with the overall experience.

The lead steward kept singing about "San Francisco" and hotel California---more annoying than humorous....needs work. Flight was smooth and on time.

Still a fan of open seating. Flight was on schedule and arrived on time. The 737 MAX is very comfortable.

Airline travel is always too cramped to really be pleasant, but the cabin crew on this flight did a pretty good job of making up for it by putting on some music during boarding and sprinkling a few funny remarks into the safety briefing and announcements, and just generally being friendly and helpful. It definitely reminded me of why I prefer the in-flight experience on Southwest!

No delays and arrived to destination 30 min early. Staff was super friendly.

San Diego airport is brand new, spacious, airy and very smooth checkin at SW baggage drop.

It was rough. The staff was unprofessional, the choice of on board drinks terrible, it was cramped in space at every airport, they always ran out of overhead bin space so they pressured people to check bags for free or we couldn’t leave on the plane— so I did check my bag to help, and they nearly lost my bag. My bag did not arrive on the luggage belt, another man on my flight and I had to waste our time going to the baggage office to search for our bags. I would only fly southwest again if it was my last choice. Also, my flights were consistently delayed over and over again— at one point they straight up told us we were waiting for the pilot to arrive.

Crew could have been friendlier, maybe I'm spoiled by SW crews. In flight wifi was good. Would be nice to have more food offerings on a 4 plus hour flight

Had to get off plane from prior flight even though I had to reboard same plane to continue to my final destination.

I am extremely disappointed that delta internal pilot manuals now refer to the Gulf of Mexico as the “gulf of America”. You can bow down to the Orange turd on your own. I will never fly delta again

Wasn't a Delta issue I don't think, but seems there was a Delta flight at each of the 2 Dallas airports at the same exact time, both to Atlanta. I was evidently booked on the one at Love Airport, but the Carey transport shuttle took me to DFW instead and I ended up missing the flight by just a few minutes. Was able to book a Southwest flight from Love Airport, but was a big loss of time and an inconvenience.

Great. I had to modify a flight. That was easy and free. Thank You

I noticed that the planes seem to be outdated. There was no entertainment per se. Also, the waiting area did not have any working electrical outlets

Original flight was cancelled and when i was rebooked by the airline, they couldn't seat me in the same type of seat as I had originally booked (went from window/aisle to middle/middle and one was a bulkhead seat, and other wasn't in the same class)

Lady Pilot was perfect in every way wheels up to wheels down communication, professionalism, excellent on time departure and on time arrival, excellent communication! Fantastic job with Superb attitude!!

The food is terrible. The staff is wonderful. Comfort is good.

Left on time, a bit delayed due to headwinds most of the trip.

I fly Delta all the time, have Platinum Medallion status. But this route seems to have major problems with delays and seems to never leave on time! Have only taken it twice in the last two weeks, and each time it had delays of more than 1 hour... very disappointed!!!!

Good seats in Main cabin, excellent service and excellent landing

The flight was on time. I generally don’t drink or eat on short flights and the seats were good and the flight attendants were friendly. That’s all I expect

It was nice to have gotten up upgraded to first class with a meal on a three hour flight

Very bad! They kept delaying my flight and wouldn’t do anything about it

Door to door, the crew and staff were amazing. It was a stressful travel day with delays, but they were focused on customers and doing what they could to get us to our destinations.

Flight was delayed only slightly before takeoff due to traffic control. However, the flight arrived early to ORD. Good flight. United has been very reliable for me.

Another delayed flight. When the delays exceed the duration of the flight, it’s a problem.

After boarding the plane in Chicago, the passengers were told that there was a technical problem with the plane. Passengers remained on the plane as they tried to fix the problem. After what was probably an hour passengers were told that there was a need to change planes as the problem was not solved. Passengers disembarked and boarded another plane. After taxing to the runway and waiting for takeoff, passengers were told that owing to the thunderstorm the flight was unable to take off but would try and reroute. After some time passengers were told there wasn't enough fuel for the new route and the plane had to return to the gate for additional fuel. after another log delay the flight got underway. On the plane there was food, drinks, ice or entertainment. We were a glass of water, which appeared rationed. Flight arrived about 5 hours late. The pilot was fantastic and communicated with the passengers throughout the ordeal.

Better WiFi. I cannot understand that in 2025, United is so behind on a technology that is now a necessity and still painfully unreliable, slow and keeps disconnecting.

Trip was great. A wild landing in Ottawa with the wind and rain, but the pilot did a great job. Always love flying United.👍

Excellent experience. Starting with the agent at the Premier bag drop who noticed I was very early for my scheduled flight and offered to rebook me on an earlier flight with my seat preference. She would not let me leave the counter until she knew that all of the changes and new boarding pass showed up on my United app. At the gate, the flight boarded quickly such that we departed early and the flight was smooth. We arrived 20 minutes early at ORD and I was able to be home in time for dinner. One of the best flights I've had.

Awful. They won’t help me with anything. I booked on American but they abdicated to Iberia. The ticket was overpriced. Everything negative

I enjoyed the extra leg room compared to other airlines. The first stewards made my daughter’s birthday special by giving her an extra snack. Then the last one coming home from Chicago to Appleton made our night really enjoyable Thanks for making our trip enjoyable

It was good..clean, comfy seat. Friendly warm welcoming crew. Was able to check my cabin luggage at the gate which I was able to pickup in a decent time from baggage claim. The app gave all updates from delays to baggage claim info. Overall smooth flight.

It was a typical flight. We had a delay which seems to be the normality now. And we had no in flight service due to conditions.

After we landed we sat on the tarmac for 1.5 hours waiting to get to our gate. Ridiculous.

Terrible. Flight delayed for more than 8 hours with only a $12 meal voucher provided for the inconvenience. The airplane did not have breaks on arrival yet they still made us go through the motions and board on time knowing we could not take off then sit for 40+ minutes before having to get of the time. A complete waste of my time. I cannot believe they can stay business with these shenanigans. I’ll avoid this company like the plague moving forward as the lack of accountability is disgraceful.

This was the best 2 flights I have had with American out of SGF. Great crew both flights.

Excellent - explanations were clear staff was nice and flight was comfortable

Lost bag and 2 days no word leaving for cruise no clothes or stuff

Any flight to ORD after about 2pm this summer has been challenging. Flight was delayed getting in (coming from ORD) and that led to it not leaving before a ground stop due to lightening before they could fuel the plane, and so forth. They made up some time but we were still late in arriving at ORD, and that led to missed connections.

Not clean and was told I would get a great seat and it was not great at all

Flight got delayed for 5 hours no good explanation was offered ;(

Horrible. I would never fly Frontier again. The booking process is tricky at best, but fraudulent in my opinion. Frontier customer service did nothing to rectify my purchase -- I ended up paying more than double what I could have gotten from other airlines and nearly triple what I thought I was buying from Frontier. Their booking practices are unfair to the consumer.

Delayed. Text notifications were slow. Not much information o what was happening. Boarding was slow and confusing. Wasn’t even offered water other flight. Had to ask. No entertainment at all. Felt like.a Greyhound bus.

When I wanted to check in 3 hours prior to boarding time, the employees mentioned “a little over an hour delay” so I waited for an hour then I went to go look for food in the terminal and most people from that flight were in the same area looking for food. Finally I decided after food to check to see if it’s anytime closer and now it’s 2 mins until boarding closes?! What are you kidding me? I didn’t receive anything via sms about boarding now nor via email or on the intercom. I luckily made it through, barely, and then there’s no room for my carry on mind you I’m in the very first row so I had to place my purse in one further row back and my carry on sections down. Not sure who pays for better seats to get your stuff placed all over the plane but that was the worst experience I’ve ever had flying with anyone.

Better than expected. Staff were friendly and nice on both flights.

There was no one at the counter to assist with our check in. The app didn’t work, so I arrived at the airport with time to check in and I couldn’t because no employees were there. When I finally got someone on the phone, it was inside the 60min rule and they said I could no longer check in and they could sell me another ticket. We had to scramble and pay an additional $800 for tickets and THEN AFTER (about 60 min from my original convo with customer service and 10min after original departure time) I had boarded my new flight, there was email saying my original flight from Frontier was delayed and leaving 2hr 50min later, but I STILL wouldn’t have been able to check in. Which means customer service should have been able to see it and let me check in because I was well within my check in time. When I call Frontier, they hang up on me. So their app didn’t work and they employees left and they take zero responsibility or assistance with their “customer service”

Terrible. Flight cancelled with no reasoning and no flights to rebook. Employees were useless and did nothing to help. Did not even know where to retrieve luggage from the cancelled flight. Flyers beware.

No fault of Frontier staff: plane was very late, reached Orlando at 1 am, took a while to get luggage. Weather, gov financial shutdown impact on TSA, air controllers seemed to have multiple flights backed up. Frontier staff seemed to cope as gracefully as possible. It did reassure me that I and my new hip could adapt to travel challenges. Food/entertainment were irrelevant to my trip.

Terrible. The canceled my entire flight when I requested a refund for a trip frontier canceled trip one way.

Everything you need to know for your flight to Waterloo

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