Frontier Airlines is a major ultra-low-cost American airline headquartered in Denver, Colorado. It operates flights to over 100 destinations throughout the United States and 31 international destinations, and employs more than 3,000 staff.

In 2026, Frontier Airlines is primarily known as a Ultra-Low-Cost Carrier (ULCC) that uses an "unbundled" pricing model—meaning you pay a very low base fare and then pay extra for everything else, including carry-on bags and seat selection. They are iconic for their animal tail art, where every aircraft features a different named animal like "Griz the Bear" or "Francie the Frigatebird." In 2026, Frontier has also become famous for its GoWild! All-You-Can-Fly Pass, which allows travelers to book unlimited flights for a fixed annual fee. Most recently, they have attempted a "reset" in 2026 by introducing a premium seating section with extra legroom to appeal to more than just budget travelers. Despite its reputation for high fees and basic service, Frontier is recognized for operating one of the youngest and most fuel-efficient fleets in America, making it a popular choice for eco-conscious travelers on a budget.