They'll face Kilmacud Crokes who were comfortable winners over Portarlington.
The Downs are into their first Leinster final in 50 years.
Lar Wall's side edged past Ratoath by 2-12 to 17 points.
Luke Loughlin starred for the Westmeath champions hitting five points, the dual code man was named player of the match in Saturday's first semi final.
They'll face Kilmacud Crokes who enjoyed a comfortable 1-12 to 4 point-win over Portarlington at Croke Park.
Loughlin says credit has to go to the side's manager Lar Wall: