Zachary Douglas Apple (born April 23, 1997) is a retired American competitive swimmer who specialized in the sprint freestyle events.

[4] He competed at the 2019 World Aquatics Championships held in Gwangju, South Korea, winning four medals – two gold, one silver, and one bronze.

[9] Apple attended Edgewood High School and swam for GMVY Wahoos club team.

[12] In his sophomore year, Apple tied for fourth place in the 50-yard freestyle at the 2017 Men's NCAA Division I Championships.

[21] At the 2019 World Aquatics Championships held in July in Gwangju, South Korea, Apple won a total of four medals, two golds, one silver, and one bronze, all in relay events.

[23] Swimming with Caeleb Dressel, Mallory Comerford, and Simone Manuel in the final of mixed 4x100-meter freestyle relay, Apple won a gold medal and helped set a new world record of 3:19.40.

[34][35][36][37] All relay teammates, including prelims-only swimmer Brooks Curry, won the gold medal for their efforts.

[39] On the fourth day of competition, Apple swam a 48.16 in the prelims of the 100-meter freestyle, ranked 11th overall, and qualified for the semifinals.

[31][40] The following day of competition, Apple was selected to swim in the finals of the 4x200-meter freestyle relay along with Kieran Smith, Drew Kibler, and Townley Haas.

[31] On the final day, Apple swam the freestyle leg of the 4x100-meter medley relay and won a gold medal and set the world record and Olympic record in the event at 3:26.78 along with his final relay teammates Ryan Murphy, Michael Andrew, and Caeleb Dressel.

[47][48] For the 2021 International Swimming League, Apple was selected as a member of the team DC Trident roster.

[3] Apple entered to compete in one individual event at the 2021 World Short Course Championships in Abu Dhabi, United Arab Emirates in December, the 100-meter freestyle.

[61] In the final, Ryan Held substituted in for Apple and the relay team won the silver medal with a time of 3:20.50.

[64] For the prelims of the 50 meter freestyle on day three, he ranked 14th with a 22.96 and qualified for the b-final in the evening where he went on to place eighth, sixteenth overall, with a time of 22.97 seconds.

[66][65] At the 2022 US International Team Trials in Greensboro, North Carolina, Apple ranked seventh in the prelims heats of the 100 meter freestyle on the first day of competition, qualifying for the evening final in 48.57 seconds.