The Onex, Sonex, Waiex and Xenos are a family of lightweight, metal, low-wing, two seat homebuilt aircraft. Kits are produced and marketed by Sonex Aircraft, a small manufacturer based in Oshkosh, Wisconsin. By 2014, 500 customer built aircraft had been completed. The Sonex can also be built from plans.

The Xenos is a light, aluminum, low-wing, two seat homebuilt aircraft, that can be registered as a motor glider or a light-sport aircraft (ELSA). Kits are produced and marketed by Sonex Aircraft, a small manufacturer based in Oshkosh, Wisconsin.