The 20th annual event focuses on fundraising and bringing awareness for Special Olympics Illinois.
More than 82,000 rubber ducks splashed down and raced down the Chicago River, Special Olympics Illinois said.
Longtime athlete Zach Coppel of Highland Park served as the official Duck Ambassador for the derby.
"Each donation supports Special Olympics Illinois programming which creates opportunities for growth, personal development, and connection through, sports, health, and leadership programs for individuals with intellectual disabilities," said Pete Beale-DelVecchio, president and CEO of Special Olympics Illinois.
The derby festival began at 10 a.m. at Pioneer Court on Michigan Avenue, with games, food trucks, souvenirs, photo opportunities and music.
The official duck splashdown happened at 1 p.m. off of the Columbus Drive Bridge.
Illinois Secretary of State Alexi Giannoulias served as honorary race marshal.
To enter the race, participants can adopt a duck starting at $10 and each entry comes with a chance to win prizes, including a Chevy Trailblazer, a $2,500 cash prize or W Club Chicago Cubs tickets.