Wingsuit flying is the sport of flying the human body through the air using a special jumpsuit, called a wingsuit, which adds surface area to the human body to enable a significant increase in lift. Modern wingsuit designs create the surface area with fabric between the legs and under the arms. A wingsuit may be referred to as a birdman suit or squirrel suit.

A wingsuit flight ends with a parachute opening, so a wingsuit can be flown from any point that provides sufficient altitude to glide through the air, such as skydiving aircraft or BASE jumping exit points, and to allow a parachute to deploy.

The wingsuit flier wears parachute equipment designed for skydiving or BASE jumping. The flier deploys the parachute at a planned altitude and unzips the arm wings, if necessary, so they can reach up to the control toggles and fly to a normal parachute landing.

Wings were first used in the 1930s as an attempt to increase horizontal movement. These early wingsuits were made of materials such as canvas, wood, silk, steel, and even whale bone. They were not very reliable. Some "birdmen", notably Clem Sohn and Leo Valentin, claimed to have glided for miles. The wingsuit was showcased in the 1969 movie The Gypsy Moths starring Burt Lancaster and Gene Hackman.