$928 Find Cheap Flights from Knoxville to Portugal

This is the cheapest round-trip flight price found by a KAYAK user in the last 72 hours by searching for a flight from Knoxville to Portugal departing on 9/19. 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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Cheap Flights from Knoxville to Portugal

Cheapest round-trip prices found by our users on KAYAK in the last 72 hours
Lisbon
Lisbon2 stops$928
Porto
Porto2 stops$868
Lisbon
Lisbon2 stops$928
Porto
Porto2 stops$868

Book Cheap Knoxville to Portugal Plane Tickets

 
Here are some of the best deals found on KAYAK recently from the most popular airlines for round-trip flights from Knoxville to Portugal 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 from Knoxville to Portugal

Sat, Sep 19 - Wed, Sep 30
United Airlines Logo
7:19 pm - 8:20 am
TYS
-
LIS
32h 01m
2 stops
United Airlines Logo
5:05 am - 9:59 am
LIS
-
TYS
33h 54m
2 stops
$928United Airlines
Sat, Sep 19 - Wed, Sep 30
United Airlines Logo
7:19 pm - 8:20 am
TYS
-
LIS
32h 01m
2 stops
United Airlines Logo
12:20 pm - 11:55 pm
LIS
-
TYS
16h 35m
1 stop
$933United Airlines
Tue, Jul 21 - Thu, Jul 30
Delta Logo
5:40 am - 8:00 am
TYS
-
LIS
21h 20m
2 stops
Delta Logo
5:00 am - 11:01 pm
LIS
-
TYS
23h 01m
2 stops
$952Delta
Sat, Jul 4 - Wed, Jul 15
United Airlines Logo
7:19 pm - 9:20 am
TYS
-
LIS
33h 01m
2 stops
United Airlines Logo
6:45 am - 10:34 pm
LIS
-
TYS
20h 49m
2 stops
$959United Airlines
Tue, Jul 21 - Thu, Jul 30
United Airlines Logo
7:19 pm - 10:30 am
TYS
-
LIS
10h 11m
1 stop
United Airlines Logo
1:00 pm - 11:54 pm
LIS
-
TYS
15h 54m
2 stops
$967United Airlines
Sat, Jul 4 - Wed, Jul 15
United Airlines Logo
7:19 pm - 9:20 am
TYS
-
LIS
33h 01m
2 stops
United Airlines Logo
12:20 pm - 11:54 pm
LIS
-
TYS
16h 34m
1 stop
$968United Airlines
Tue, Jul 21 - Thu, Jul 30
British Airways Logo
6:00 am - 9:05 am
TYS
-
LIS
22h 05m
1 stop
British Airways Logo
11:05 am - 6:08 pm
LIS
-
TYS
12h 03m
1 stop
$993British Airways
Fri, Jul 10 - Fri, Jul 17
United Airlines Logo
5:45 am - 9:20 am
TYS
-
LIS
22h 35m
2 stops
United Airlines Logo
11:25 am - 10:34 pm
LIS
-
TYS
40h 09m
2 stops
$1,002United Airlines
Sat, Sep 19 - Wed, Sep 30
British Airways Logo
6:21 am - 9:05 am
TYS
-
LIS
21h 44m
1 stop
British Airways Logo
11:05 am - 9:54 pm
LIS
-
TYS
15h 49m
1 stop
$1,015British Airways
Wed, Jun 17 - Wed, Jun 24
Air Canada Logo
1:54 pm - 5:20 pm
TYS
-
FAO
22h 26m
3 stops
Air Canada Logo
6:05 am - 11:54 pm
FAO
-
TYS
22h 49m
3 stops
$2,051Air Canada
Booking Insights

KAYAK's insights & trends for Knoxville to Portugal flights

Get data-powered insights and trends into flights from Knoxville to Portugal to help you find the cheapest flights, the best time to fly and much more.

What is the cheapest month to fly from Knoxville to Portugal?

To calculate monthly average prices, KAYAK takes all prices for each month over the last year for round-trip flights from Knoxville to Portugal, removes the top 0.1% to account for outliers, and then takes the median of all values for each month.

The cheapest month for flights from Knoxville to Portugal is December, when tickets cost $475 (return) on average. On the other hand, the most expensive months are June and November, when the average cost of round-trip tickets is $1,549 and $925 respectively.

Good to know

Low seasonFebruary
Cheapest flight$928
Best time to beat the crowds with an average 48% drop in price.
Most popular time to fly and prices are also 15% lower on average.
Flight from Knoxville to Lisbon

FAQs - booking Portugal flights

  • How does KAYAK find such low prices on flights from Knoxville to Portugal?

    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 from Knoxville to Portugal.

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

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

  • What is the Hacker Fare option on flights from Knoxville to Portugal?

    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 from Knoxville to Portugal 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 from Knoxville to Portugal?

    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 from Knoxville to Portugal up to 3 days before/after your preferred dates. You can then pick the flights that suit you best.

Reviews of the top 3 airlines serving from Knoxville to Portugal

 
Need help choosing which airline to fly with from Knoxville to Portugal? 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.
7.4
United AirlinesOverall score based on 9684 reviews
8.1Crew
7.7Boarding
7.1Entertainment
6.6Food
7.3Comfort
Airline reviews

Left an hour and a half after the listed time. Up side was it had TV screens on the seat.

4.0 OkayMaya, May 2026
IAH - MIA
Read more United Airlines reviews

Left an hour and a half after the listed time. Up side was it had TV screens on the seat.

No screens or meal options. Freezing cold. Dirty seats. Left late.

O’hsre taxi and deboarding took 40 minutes. Needed 20 minutes extra time between connecting flights to avoid running through terminal.

Cree was organized and pleasant. Plane had good seating but as it’s a shuttle toilets hadn’t been thoroughly cleaned (eg. bins too full)

I liked that my son and I were reseated next to each other (we had different bookings). I liked that it was a directg flight and mostly on time. I liked that you provided pillows and blankets. Flight attendants were generally courteous. The messaging through wifi did not work well. The food was not good. Seats are very narrow and I felt slightly claustraphobic in the window seat.

Overall a good experience, but no wifi available for free or for purchase and we got wet from condensation or other water source during descent.

Some crew were unfriendly or in some cases just straight up rude.

Booked through Kayak Business, had a seat in middle and towards back due to booking rate, not comfortable.

Was great in general, try to respect time and excuses when slight changes have been made, appreciated!

A long delay. Don't travel late in the day.

Terrible, horrible, disappointing- without telling us they changed planes and moved and separated our seats to opposite sides - said they changed seats putting us together - got to airport to find no, they did not - we sat opposing sides of plane - food overly salty to inedible, never saw stewardess but once - it was terrible

not sure why you ask about food, I n3ver get food on flights except maybe cookies or pretzels. wifi was slow and in and out most of the flight not good.

The crew was very attentive through out the flight. Seats were comfortable, nice flight bag with pillow and blanket. Food was okay, since it was a overnight flight seemed to go by fast.

The flight attendant on my side of business class seemed like a novice and did not provide good service. Otherwise the flight was good and the entertainment system was very good. No free WiFi.

Cancelled BOYH legs of our flight home 30 min before initial boarding

Cancelled the flight half hour before boarding. Then cancelled the connecting flight too.

Left early arrived early..right amount of talking from pilots..of course had to love the biscuit and water!

I would like a refund for the extra cost the seat I paid for. An oversized person sat next to me and I couldn’t fit on my seat and had to move to another seat.

Boarding gate at LAX was too crowded—two gates next to one another

The flight was delayed about an hour for a maintenance specialist to approve the maintenance repair

Someone switched seats in business class so they could sit together and we were left apart (3). Very disappointing. Staff did nothing

Somone switched seats to sit near friend causing us to be disconnected (3) business class. Very disappointed. Staff did nothing.

Boarding was orderly, pilot and flight attendants were nice, entertainment options were good, and low sodium meals were quite tasty.

The whole experience was excellent, O can say out from Miami the best airline to travel with for any European destination. Since the ground staff to the inflight crew attention was great, service on board 10 of 10. Finally the 380 is very confortable and nice to travel.

All crew except 1 were excellent. When I asked assistance with business class seat conversion to a bed (not being familiar as never used before but have numerous times with other airlines) crew member helped very reluctantly. I should have told her that business class seat conversion is totally different in each airline such as Delta, New Zealand Air and United. Sorry it was my 1st time with America Airlines. Now I know, I won't bother asking assistance in future.

1st class seats NOT REALLY 1st class or business class but like premier economy. Should be listed as such or named something else. I have flown 1st class with other airlines and they are nothing like it at all.

The seats in Premier Economy were very comfortable. The food was better than average. The way British Airways handled our seating was atrocious.

Worst airline in the world. They downgraded me from business class to economy with no compensation.

Flight delayed, connection was not at gate listed and so missed, staff were rude at Heathrow, phone tree stupid and difficult, took me 21 actual hours to reach my destination. Almost lost my hotel reservation after walking in a strange city alone after midnight because they would not put me up in a hotel at sfo or heathrow. I will never fly BA again and will tell all people and Instagram followers never to fly BA.

Overall ok. Best part has always been the sundae dessert.

Everything you need to know for your flight from Knoxville to Portugal

Information on your arrival and departure airports