Donald Gene Clary Jr. (born July 29, 1957) is an American former long-distance runner who competed mainly in 5000 meters and cross country running.

He represented the United States at the 1984 Summer Olympics and competed three times at the IAAF World Cross Country Championships, taking a junior title in 1975 and a senior team silver medal in 1980.

At the 1978 NCAA Division I Men's Cross Country Championships he placed seventh and was runner-up in the team rankings alongside classmate Alberto Salazar.

[1] His senior international debut came at the 1980 IAAF World Cross Country Championships, where his 43rd-place finish ina team of Craig Virgin (the winner), Daniel Dillon, Kenneth Martin, Steve Plasencia, and Mark Anderson brought the Americans the silver medals.

[5] He began to focus on track running more and progressed up the national rankings, taking fifth in the 5000 meters at the 1980 United States Olympic Trials then third at the 1981 USA Outdoors.