Adelaide T. Lambert (October 27, 1907 – April 17, 1996), also known by her married name Adelaide Ballard, was an American competition swimmer who earned a gold medal as a member of winning U.S. team in the women's 4×100-meter freestyle relay at the 1928 Summer Olympics, setting a new world record in the process. Lambert was the Amateur Athletic Union (AAU) champion in freestyle, backstroke, and the individual medley events.