The Leinster Junior Football Championship was a junior "knockout" competition in the game of Gaelic football played in the province of Leinster in Ireland.

The winners of the Leinster Junior Football Championship each year would then progress to play the other provincial champions for a chance to win the All-Ireland Junior Football Championship.

At GAA Congress in 2021, a motion was passed to change the entire structure of the All Ireland Junior Football Championship competition to that of a mostly 'overseas competition' along with just one Irish county, Kilkenny.

Hence there is no longer any Leinster Junior Football Championship competition.

(* 1924 Longford awarded the title following an objection to Meath playing a Senior player.