Where does frontier fly? Frontier Airlines is a low-cost carrier that primarily serves domestic destinations within the United States, as well as some international locations in Mexico and Canada. With its focus on affordability and convenience, Frontier flies to a wide range of cities across the country, including popular destinations like Las Vegas, Orlando, Denver, and New York City. Whether you're planning a weekend getaway or a business trip, Frontier offers a variety of flight options to suit your needs.