HomeSearch by dateVacation packagesHotelsFlight dealsCar rentalTravel tips & news
Porto

Find cheap United Airlines flights to Porto

RDU — OPO
Aug 26 — Sep 21
Wed 8/26
Wed 9/2
1 adult, Economy
We work with more than 300 partners to bring you better travel deals

Leverage Cheapflights for Your Next Trip

1. Tell us where you want to go

Enter your travel information like dates, passengers, trip type (one-way or round trip), and preferred cabin class then click “Find deals”

2. Select your favorite providers

We find the providers serving your travel needs. Choose up to four travel providers to compare side-by-side for flights, hotels, or car rentals.

3. Compare prices and book

Review each provider’s pricing and select the best option for you! Book through your favorite provider’s website for a seamless experience.

Find United Airlines flight deals to Porto

Cheapest United Airlines flights from USA to Porto
Explore the most affordable United Airlines flight options available from USA to Porto. Find the lowest fares with prices last updated on July 27, 2026.

This United Airlines deal was found by Cheapflights users on 7/22. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Wed 8/195:00 am
SFO
-
OPO
2 stops18h 00m
United Airlines
Wed 9/211:20 am
OPO
-
SFO
2 stops32h 05m
United Airlines
Deal found 7/22$842
This United Airlines deal was found by Cheapflights users on 7/27. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/95:45 am
BOS
-
OPO
2 stops23h 00m
United Airlines
Sat 12/512:35 pm
OPO
-
BOS
2 stops16h 19m
United Airlines
Deal found 7/27$844
This United Airlines deal was found by Cheapflights users on 7/23. Clicking the “Pick Dates” button in this card will allow you to select your dates and further customize your flight criteria. From there, click “Find deals”, make sure United Airlines is selected, and click “Compare selected” under the list of providers to see comparable flight deals.
Sun 8/236:50 pm
EWR
-
OPO
Nonstop7h 05m
United Airlines
Tue 9/112:15 pm
OPO
-
EWR
2 stops29h 09m
United Airlines
Deal found 7/23$869

Flights to Porto with United Airlines at a glance

Find detailed information about United Airlines flights from USA to Porto. Explore the options provided by United Airlines to plan your journey from USA to Porto. Data last updated July 27, 2026.

Popular in

May

Cheapest in

February

Average price

$882

Round-trip from

$668

One-way from

$334
Highest demand for flights to Porto with United Airlines; 14% potential price increase.
Search Deals
Best time to find cheap flights to Porto with United Airlines; 2% potential price drop.
Search Deals
Average price for flights to Porto with United Airlines (round-trip).
Search Deals
United Airlines
  • United Airlines
  • 10/14-11/10
  • 4 total stops
  • 40h 08m total
  • USA to Porto
Search Deals
United Airlines
  • United Airlines
  • 10/27
  • 2 total stops
  • 20h 30m total
  • USA to Porto
Search Deals

Cheapflights Insights

Find cheap United Airlines flights to Porto

How long is the flight to Porto with United Airlines?

On average, United Airlines flights from the United States to Porto take 8 hours 23 minutes. Flights to Porto from other popular cities in the United States will vary in length. Below are a few examples of popular routes and their flight times.

United Airlines weekly flight availability to Porto

The most flights to Porto operated by United Airlines are scheduled on a Monday (2 on average). You will have fewer flight options on Monday, which is when the least amount of flights are scheduled (2 on average).

When is the best time to book a flight to Porto with United Airlines?

The best time to book a flight to Porto with United Airlines is 85 days before departure. On average, fares are higher if you book 1 day before departure.

FAQs about flights to Porto with United Airlines

  • Which airport do United Airlines flights arrive at when travelling to Porto?

    United Airlines flights on this route tend to land at Porto Airport.

  • Is United Airlines the cheapest airline for a flight to Porto?

    Flight prices will depend on many factors like date, time and cabin class so it is worth comparing flights before booking. Based on Cheapflights data the cheapest average return price for flights to Porto tends to be with Scandinavian Airlines.

  • Are there alternative airlines other than United Airlines that fly to Porto?

    TAP AIR PORTUGAL, Delta and KLM all fly to Porto and offer an alternative to United Airlines.

  • How much is a flight to Porto with United Airlines?

    The average price for a return flight with United Airlines is $1,008; with a one-way flight around $562.

See more FAQs

Reviews of United Airlines

See what Cheapflights users have to say about their United Airlines experience.
United Airlines
7.4
Good
10,000 reviews
Overview

Boarding

7.7

Comfort

7.3

Crew

8.1

Food

6.6

Entertainment

7.1

Popular United Airlines flights

Toggle through the tabs below to find thousands of options on Cheapflights for your next trip.