YD

YD, or Yd may refer to:


 * Yard (yd), a unit of length
 * Nissan YD engine, an automobile engine
 * Yarmouth–Dennis Red Sox, or Y-D Red Sox, a collegiate summer baseball team based in South Yarmouth, Massachusetts
 * Younger Dryas, a geological period from c. 12,900 to c. 11,700 calendar years ago
 * South Yemen (ISO 3166-1 code YD)
 * A US Navy hull classification symbol: Floating derrick (YD)
 * YD - Young Diem / Early Day
 * Yd. (retailer), an Australia and New Zealand clothing retail chain