Leading Edge Air Foils LLC (formerly Leading Edge Air Foils, Inc.), usually called LEAF, is an American aircraft parts supplier based in Lyons, Wisconsin.

[1][2][3][4][5][6] The company was founded by Bill Raisner in Peyton, Colorado, in the 1980s and claims to be the oldest ultralight aircraft parts supplier.

[1][2][3][4][5][6] The company is owned by Bill Read and Mary Myers and is part of the Wag-Aero group of companies.

[6] LEAF at one time offered kits and parts for other designer's aircraft, such as Dennis Wiley's Early Bird Jenny, Graham Lee's Circa Reproductions Nieuport, the J & J Ultralights Tukan and Antares MA-32 ultralight trikes, as well as two of Raisner's own designs, the Raisner Graffiti two seat trike and the LEAF Trike single seat trike.

The company has long been a Rotax aircraft engine dealer and overhaul facility.