Patrick Leahy Burlington International Airport (IATA: BTV, ICAO: KBTV, FAA LID: BTV) is a joint-use civil-military airport serving Burlington, Vermont's most populous city, and its metropolitan area. Owned by the City of Burlington, the airport itself is located in neighboring South Burlington, just three nautical miles (6 km) east of Burlington's central business district.

It is by far the busiest airport in Vermont, with 100 times the traffic of the second-busiest, Rutland–Southern Vermont Regional Airport. It is the only airport in the state with mainline commercial service. As of 2015, around 40% of the airport's passengers come from Quebec, Canada.

In 2019, the airport had 687,436 passenger boardings according to Federal Aviation Administration (FAA) records, an increase of 4.33% from the year prior. This airport is included in the FAA's National Plan of Integrated Airport Systems for 2021–2025, which categorized it as a primary commercial service airport (more than 10,000 enplanements per year).

The airport serves as the base of the 158th Fighter Wing, Vermont Air National Guard and an Army Aviation Support Facility (AASF) of the Vermont Army National Guard and the Vermont State Guard.

In 2023, the airport was renamed to honor former U.S. senator Patrick Leahy.