They beat Mayo by 2-11 to 1-7
Roscommon are the new Connacht under-20 Football champions.
Adam McDermott and man of the match James Fitzpatrick scored second-half goals as they beat Mayo by 2-11 to 1-7 at McHale Park last night.
Dublin have the chance to win their third successive Leinster under-20 Football title tonight.
Last year's beaten All-Ireland finalists take on Offaly at O’Moore Park at half-seven.
The Munster under-20 Football decider pits Tipperary against Cork at the same time at Semple Stadium.
Tipp are unchanged from their win against Waterford in the semis while Cork are aiming to win their second title in three years.