This Popular US Airline Had The Most Delayed Flights In 2025

Budget airlines often make headlines for the wrong reasons. Ryanair caused a stir around the world when its CEO suggested creating an impossible-sounding "standing room only" fare class. Other airlines offer inexpensive fares, but with sneaky hidden fees — in fact, if you're flying on the cheap, you'll likely have to pay for even a simple drink of water. And now, just ahead of the busy travel season around Christmas and New Year's, a report from the flight information app Flighty has revealed that the U.S. carrier with the most delayed flights in 2025 was the Denver-based budget carrier Frontier Airlines.

The news was released as part of Flighty's 2025 Global Passport Report, a Spotify Wrapped-style review of the year in travel. The report evaluated information collected from over 22 million flights taken by the app's users between January and November 2025. Worldwide, the airline with the most delayed flights was Ryanair, with Air France and easyJet not far behind. But in the United States, Frontier took the top spot, with 28% of flights landing at least 15 minutes behind schedule.

Trailing behind Frontier were Southwest Airlines and JetBlue Airways, each with a quarter of flights delayed by at least 15 minutes (compared to the industry standard of 22%). The other U.S. airlines that made the top five list, in terms of most delayed flights, were American Airlines and Alaska Airlines. To be fair, across the board, more than 40 percent of flights arrived at least one minute late: the average delay, on a global scale, is 23 minutes. 

But those minutes add up. Flighty's report notes that the difference between scheduled arrival times and actual arrival times totaled nearly four million hours. The Flighty app has a special feature, "get me off this plane," that allows users to calculate when they'll actually be able to, well, get off the plane — a handy insight, given that nearly a third of flights are delayed on the ground after pushing back from the gate (or after landing, but before connecting to the jet bridge). 

On the other side of the spectrum is Delta Airlines, the tried and trusted classic that suffered the fewest delays, according to a January 2025 report in The Wall Street Journal. Across the pond, should you be in the market for flights between European cities, Europe's most punctual airline is the Reykjavík-based carrier Icelandair.