Harrison William Sweeny (born 9 July 1998) is an Australian professional cyclist, who currently rides for UCI WorldTeam .
Sweeny was a triathlete before transitioning to cycling.
In 2015, Sweeny came 47th in the junior individual time trial at the Road World Championships.
In 2016, Sweeny became national and continental junior champion in the time trial. He finished fifth in the continental junior road race. He finished tenth in the men's junior road race, and 20th in the men's junior time trial at the 2016 UCI Road World Championships.
In 2017, Sweeny was named as one of eight riders in the newly-formed UCI continental team Mitchelton-Scott. He continued to race for the team in the 2018 season. Sweeny came tenth overall in the general classification in the Tour de Langkawi. He held third place on general classification from stages three to six, before crashing on the final day, and losing his podium place. His best result on a stage was fourth on the third stage.
In early 2018, Sweeny was hit by a car, damaging his knee. He also suffered from a crash in Trofeo Piva and did not finish the race. He abandoned Trofeo CittÃÂ di San Vendemiano with suspected rotavirus.
Sweeny joined the EvoPro Racing team ahead of the 2019 season. He won stage three of the Rhône-Alpes Isère Tour.
Sweeny rode for the Lotto-Soudal U23, a development team for Lotto-Soudal, in 2020. He won Piccolo Giro di Lombardia, the U23 version of Giro il Lombardia. He signed for the UCI WorldTour team Lotto-Soudal for the 2021 and 2022 seasons.
In the 2025 Tour de France, Sweeny played a crucial role in helping Ben Healy take the yellow jersey on the tenth stage. Sweeny, Healy, Alex Baudin, and Neilson Powless made it into the breakaway, and rode for Healy. Sweeny rode until the Col de Guéry, before he was dropped.
Sweeny came third overall in the Tour Down Under, with his best result being a ninth place on the second stage.
Sweeny is neurodivergent; he was diagnosed with autism as an adult. He is currently the only active UCI WorldTeam rider to publicly announce this.
Sweeny has a YouTube channel where he makes videos about life as a pro-cyclist, training, and cooking.