William Ernest "Smiley" Adams (October 4, 1935 – June 19, 2003) was a trainer of Thoroughbred racehorses who trained Master Derby to win the 1975 Preakness Stakes, the second leg of the U.S. Triple Crown series. In what was the 100th running of the Preakness, Darrel McHargue aboard Master Derby defeated Kentucky Derby winner Foolish Pleasure by a full-length. Smiley Adams was retired from training and living in Nicholasville, Kentucky at the time of his passing in 2003.