The Jersey Flegg Cup is a junior rugby league competition played in New South Wales, Australia, contested among teams made up of players aged 21 or under.

The competition is administered by the New South Wales Rugby League (NSWRL), and is named for Eastern Suburbs foundation player and prominent administrator of the game, Harry "Jersey" Flegg.

[2] On 1 February 2018, the NSWRL officially announced the reintroduction of the Jersey Flegg Cup for the 2018 season after a 10-year absence.

[3] The Jersey Flegg Cup consists of 10 teams, 11 from New South Wales, 1 each from Auckland, Australian Capital Territory, Victoria and Fiji .

Beginning in early March, a round of regular season games is then played almost every weekend for twenty-one weeks, ending in late August.