Blake John Pieroni (/pəˈroʊni/ pə-ROH-nee; born November 15, 1995)[6] is a three-time Olympic gold medalist in swimming.

In March 2018 at the NCAA championships he set the American and US Open records in the 200-yard freestyle with a time of 1:29.63, becoming the first swimmer to break 1:30.

At the Tokyo Pan Pacific Championships in August 2018, Pieroni won gold with the men's relay team in the 4 x 200 m freestyle event.

At the 2019 World Championships in Gwangju, South Korea, Pieroni took home two gold medals as part of the 4 x 100 m and 4 x 100 mixed freestyle teams.

In fall of 2019, Pieroni signed for the team LA Current in the inaugural International Swimming League season.

[10] At the 2020 Summer Olympics held in Tokyo, Japan, Pieroni competed in the prelims and final of the 4x100-meter freestyle relay.

[12][13] He and all of his prelims and finals relay teammates, Brooks Curry, Bowe Becker, Caeleb Dressel, and Zach Apple, won gold for their efforts.

[15][16] On day four of competition, in Pieroni's second event at the 2020 Olympics, he advanced the 4x200-meter freestyle relay to the final in the prelims heats with his fellow prelims-relay swimmers Drew Kibler, Patrick Callan, and Andrew Seliskar.

[29][30] In the evening finals, Pieroni opted not to swim the 50-meter freestyle, focusing his efforts fully on the 100-meter individual medley where he swam a personal best time of 53.53 seconds and won the bronze medal in the event.

[43][44] In the final, he placed fifth with a time of 47.09 seconds in a talent-packed field, finishing after Kyle Chalmers, Vladimir Morozov of Russia, Kristóf Milák of Hungary, and Jesse Puts.

[49] Pieroni commenced competing in a duo of events on day one of competition with the prelims heats of the 100-meter butterfly in the morning where he ranked seventh with a time of 52.76 seconds and qualified for the final.

[50] Finishing off his morning duo of events about 30 minutes later, Pieroni ranked eighth in the prelims of the 100-meter individual medley with a time of 54.61 seconds and advanced to the final.