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 Onex is an American single-seat, low-wing aircraft first flown on 27 January 2011 and currently being produced by Sonex Aircraft as a kit for amateur construction.