John Michael "Yianni" Diakomihalis (born April 11, 1999) is an American freestyle and folkstyle wrestler who competes at 65 kilograms and 149 pounds.

[3] He made the varsity team in the seventh grade and won the Division I state championship at 99 pounds as an eighth grader, defeating future Cornell teammate Vito Arujau in the finals.

[8] As a freshman, Diakomihalis won the Bearcat Open, New York State Intercollegiate, and the Cliff Keen Invitational and compiled a record of 28-1 during the regular season.

[11] As a sophomore, Diakomihalis won the Mat Town Open I and the South Beach Individual and capped a perfect 13–0 record in dual matches, ending the regular season unbeaten.

[13] At the NCAA championships, he most notably defeated the #2, #3, and #5 ranked wrestlers in Jaydin Eierman, Joseph McKenna and Dominick Demas to claim the national title.

[16] Yianni planned to return to college wrestling in 2020–2021; however, the Ivy League announced the cancellation of all winter sports on November 13, 2020, due to the COVID-19 pandemic.

[21] Not long after, he competed in an exhibition match at the Beat the Streets charity event against multiple World medalist Bajrang Punia.

[27] In September, the rematch between Retherford and Diakomihalis took place in a special event called Final X: Yianni vs. Zain in Wilkes-Barre, Pennsylvania.

[31] After more than half a year without stepping on the mats, Diakomihalis wrestled at the annual Beat The Streets event against the heavily accomplished Vladimer Khinchegashvili on September 17.

[35] To start off the year, Diakomihalis wrestled two-time and reigning Pan American champion (70 kg) Anthony Ashnault on January 8, at the SCRTC I.

[39] Diakomihalis then competed at the America's Cup on February, defeating DI All-Americans Mitch McKee (twice) and Pat Lugo to help the Team Kenny Monday reach sixth place.

[29] After defeating the defending US Olympic Team Member Frank Molinaro, he was upset by third-seeded and 2019 US National champion Jordan Oliver, ending Diakomihalis' win streak.

[51] In May, at the 2022 World Team Trials Challenge tournament, Diakomihalis defeated Luke Pletcher and Ian Parker, both by 10-0 technical superiority, to advance to Final X against Evan Henderson.

[52] At Final X in June at Madison Square Garden, Diakomihalis defeated Henderson 11-9 and 14-4 to win the best-of-three series and earn his second straight spot on Team USA for the World Championships.

[57] His silver medal at 2022 Worlds entitled Diakomihalis to skip the preliminary qualifying rounds for Team USA and advance directly to Final X.

[59] Denver, Colorado Coralville, Iowa Warsaw, Poland Allentown, Pennsylvania Concord, North Carolina Nice, France Austin, Texas New York City Ottawa, Canada Las Vegas, Nevada Wilkes-Barre, Pennsylvania Warsaw, Poland Istanbul, Turkey New Brunswick, New Jersey New York City Las Vegas, Nevada