Janet is the de facto name for a small fleet of passenger aircraft operated for the United States Air Force. Their aircraft transport military and contractor employees and currently serve mostly the Nevada National Security Site (most notably Area 51) from their terminal at Las Vegas' McCarran International Airport. The origin of the term "Janet" is obscure and, while it is used as a radio callsign, it is not known whether it is an official name, code word or acronym.

Due to the secretive nature of the airline, little is known about its organisation. Most likely it is operated for the USAF by defense contractor URS Corporation, formerly known as EG&G; this based on the company's history of providing this service to the Air Force and job openings published by URS. For example, in 2010, URS announced it would be hiring Boeing 737 Flight Attendants to be based in Las Vegas, requiring applicants to undergo a Single Scope Background Investigation in order to be able to obtain a Top Secret security clearance. Janet flights operate with a three digit flight number and a WWW-prefix. In the official publication of ICAO airline codes, this specific three-letter designator is listed as being blocked.