Both deciders are penciled in for early January.
Offaly will be represented in both Leinster Finals at minor level for the first time since 1989.
The hurlers limited Westmeath to just once score in the second half to reach a first decider since 2003.
2-18 to 1-8 the final score, Luke Carey and Daniel Quinn with the goals.
The imperious Lochlinn Quin top scored with 10 points.
Faithful boss Leo O'Connor says the result is a reflection of the work being done across the county:
Portlaoise will also be the venue for the meeting of Kilkenny and Offaly in the minor final at 2pm on Saturday the 2nd.
The footballers will also contest the final for the first time in a decade, after beating Kildare 2-10 to 2-7.
Their manager Ken Furlong says it was a big step up from their win over Wicklow.
They'll now face Meath at Parnell Park on Sunday the 3rd at 2pm.
That's after the Royals defeated Laois in the other semi - 2-10 to 1-7.
Leinster MFC Semi-Final: Offaly 2-10, Kildare 2-07. Leinster MHC Semi-Final: Offaly 2-18, Westmeath 1-08. Happy Christmas!
Posted by Official Offaly GAA on Sunday, 20 December 2020
The meeting of Offaly and Meath in the football final and Offaly and Kilkenny in the hurling decider are due to take place during the weekend of 3rd January 2021 - although that's all dependent on covid-19 restrictions, which may put a stop to these competitions.

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