Mackenzie McDonald is an American professional tennis player who was born on April 16, 1995. On 7 February 2022, he reached a career-high singles ranking of World No. 49, and on 23 August 2021, he reached a career-high doubles ranking of No. 180. In both singles and doubles, he won the NCAA Division I Tennis Championships in 2016. McDonald received a wild card into the main draw of the US Open, where he was defeated in five sets by Czech qualifier Jan Satral in the first round. McDonald had an impressive string of results in Challenger-level tournaments from late September to early October, winning his first ITF Pro Circuit title at USA F29 Irvine Futures.
After winning the qualifiers, he played in his first Australian Open in January, defeating Elias Ymer 6–4, 6–3, 3–6, 6–1 in the first round. In the next round, he was defeated in a five-set thriller by Grigor Dimitrov, the world’s third-ranked player. Later, he defeated Jordan Thompson in the Seoul Challenger, winning 1–6, 6–4, 6–1. In the round of 64 at Wimbledon, he advanced to the third round for the first time by winning his first-ever 5-set match, 11–9 in the fifth, over Nicolás Jarry. He then went on to win in straight sets against Guido Pella, advancing to the second week of a grand slam for the first time in his career. In the round of 16, he was defeated in four sets by Milos Raonic.
McDonald reached the final of the 2019 Dallas Challenger in February, losing to Mitchell Krueger 6–4, 6–7(3), 1–6, despite leading by a set and a break in the second set. In February, he competed in the 2019 Delray Beach Open, where he won his first top 10 match by defeating Juan Martin del Potro 6–4, 3–6, 7–6(5) in the quarterfinals to advance to his first ATP level semifinal, where he lost to Radu Albot 6–3, 0–6, 0–6. His good form continued into the ATP 500 Acapulco tournament, where he advanced to the quarterfinals before losing 3–6, 2–6 to Cameron Norrie. On 4 March 2019, these results helped propel him to a career-high ranking of World No. 62.
There have been no reports of Mackenzie McDonald having a girlfriend or a wife.