The North American X-15 is an American experimental hypersonic research aircraft.
X15 or X-15 may also refer to: X-15 (band), an American rock band X-15 (film), a 1961 American drama X15 (New York City bus) BeagleBoard X15, a single board computer Bingo-Akasaka Station, in Hiroshima Prefecture, Japan Cummins X15, a diesel engine , a Q-ship of the Royal Navy Raduga Kh-15 or RKV-15 (Russian: Х-15; NATO: AS-16 "Kickback"), a Russian air-to-ground missile SJ X15, a Swedish electrical multiple unit train