Cheap KLM flights Porto (OPO) to Billund (BLL)

You can discover cheap return KLM flights from OPO to BLL by organizing your results from "Price (lowest to highest)" on Expedia. Or look for bargains for a one-way trip.**These prices were available on Expedia within the past 7 days, for flights departing within the next year. Prices and availability are subject to change. Additional terms apply.

Start your search for KLM flights from OPO to BLL about one month before you want to leave. The cheapest time to book an international flight is usually 18 to 29 days ahead of your travel date when you can save 17% versus booking four to five months in advance. No matter your fare class or itinerary, the best day to book international airfare is usually Sunday. Friday can be the most expensive. Passengers who book on a Sunday can save an average of 17% compared to those who book on a Friday.**Ideal booking window recommendation is based on average round-trip ticket prices for January through November for 2024. Best day of the week to book recommendation is based on average round-trip ticket prices for January through October 2024. All data sourced from ARC's global airline sales database.

To find the earliest departures from OPO to BLL with KLM, filter your results by "Early Morning" and "Morning." Booking an early flight generally means you'll experience fewer cancellations.**Most reliable time of the day recommendation is based on January through August 2024 flight status data sourced from OAG's global flight data platform.

Offering a 4-star airline rating, KLM is a top choice for many passengers journeying from OPO to BLL. Plus, if you're a KLM Flying Blue and One Key™ member booking through Expedia, you can earn OneKeyCash™* on eligible flights on top of your airline miles.*OneKeyCash™ disclaimer - OneKeyCash™ is not redeemable for cash and can only be used on Expedia, Hotels.com and Vrbo.