DeLeon started karting in 2008, and his first race followed five years later at Rye House Kart Raceway. The 17-year-old has since become champion in the Bizkart Rental Championship and HKC Honda Clubman category and taken wins in the finals for the Motorsport UK British Kart Championship and UKC Ultimate Karting Championship.

In 2021 he contended in a handful of Radical SR1 events, claiming a double win at Donington Park and was also a class podium finisher at the Algarve Circuit in the Radical Intercontinental Cup. 

The winning run has continued into 2022 taking another victory during the first round of the SR1 season at Donington Park in April, and a follow-up triumph at Brands Hatch. 

In 2023, Daryl DeLeon made his BTCC debut as a part of Team HARD’s line-up scoring 6 points. In 2024 he will drive for Duckhams Racing with Bartercard.