Sydney Michelle McLaughlin-Levrone (née McLaughlin; born August 7, 1999) is an American hurdler and sprinter who competes in the 400 meters hurdles and is the world record holder in that event. She is the 2020 Tokyo Olympic and 2024 Paris Olympic champion with the World and Olympic record, and 2022 World champion. She set a world record time of 50.37 seconds at the Paris Olympics on August 8, 2024, breaking her own old world record of 50.65 seconds. She is the first track athlete to break four world records in the same event: setting four world records during 13 months, she was the first woman to break the 52-second (June 2021) and 51-second (July 2022) barriers in the 400 m hurdles. She won the silver medal at the 2019 World Championships. At all three competitions, she also took gold as part of a women's 4 × 400 m relay team.
As a 15-year-old, McLaughlin was the 2015 World youth champion. In 2016, she was the youngest athlete since Denean Howard in 1980 to qualify for the U.S. Olympic track team, having placed third at the U.S. Olympic Trials, with the current world under-18 best of 54.15 seconds, then also the world U20 record. She holds the current world U20 record of 53.60 seconds, having achieved a junior personal best of 52.75 s (not ratified), with both marks set in 2018. Aside from McLaughlin-Levrone, only three other women have ever broken the 52 second barrier, and only one other has broken 51. She holds six out of the ten fastest times on the world all-time list. She was the 2019 Diamond League champion.
In 2022, McLaughlin-Levrone was voted World Athletics Female Athlete of the Year.