The 2019 Royal London One-Day Cup tournament was a limited overs cricket competition that formed part of the 2019 domestic cricket season in England and Wales. The tournament was won by Somerset, their first win in the tournament since 2001. Matches were contested over 50 overs per side and had List A cricket status. All eighteen first-class counties competed in the tournament, which due to the 2019 Cricket World Cup being hosted in England took place at the beginning of the English cricket season starting on 17 April 2019, with the final taking place just over a month later at Lord's on 25 May 2019. Hampshire were the defending champions.