XS1

XS1 may refer to:
 * The original designation, XS-1, of the Bell X-1, a supersonic prototype airplane designed and built by the United States in 1945
 * XS-1 (spacecraft), a DARPA experimental spaceplane
 * Fujifilm X-S1, a superzoom digital bridge camera released in November 2011
 * XCore XS1 microprocessor