Donald Ward McKenzie Jr. (May 11, 1947 – December 3, 2008) was an American competition swimmer, Olympic champion, and former world record-holder.

[3] He competed at the 1968 Olympic Games in Mexico City, where he received a gold medal for winning the men's 100-meter breaststroke.

The first-place team of Charlie Hickcox, McKenzie, Doug Russell and Ken Walsh set a new world-record time of 3:54.9 in the event final.

[6] He was also inducted posthumously into the Los Angeles Valley College Athletic Hall of Fame in 2011.

[8] As the president of Practice Management Services, he created and supported computer software and systems for medical, dental, and small businesses.