They defeated St Cillian's on Sunday by seven points.
Birr secured back-to-back Offaly Senior Camogie Championship titles at the weekend.
They claimed a 1-15 to 0-11 win over St Cillian's in St Brendan's Park in Birr to make it two-in-a-row.
Sarah Harding got the only goal of the game, with Mairead Jennings ending the game with 0-09 and Sheila Sullivan producing a Player of the Match performance.
Birr will now represent Offaly in the Leinster Championship.
Meanwhile, St Rynagh's struck two late goals to see off Kilcormac-Killoughey in the Senior B decider.
The game ended 2-10 to 2-05.
Keeping Up Unbeaten League Start The Aim For Athlone Town Women
Two Pointer Rule Makes Big Difference To Gaelic Football - Emmet McDonnell
Shane Lowry Records Opening Round Of 72
Tullamore Town FC Ready For Red Letter Weekend
Busy Bank Holiday Weekend In Store For Athlone Town
Big Weekend Ahead In Leinster Minor And U20 Hurling Championships
Leinster SFC: Opportunity Beckons For Westmeath
Westmeath Footballer Luke Loughlin Ruled Out For Remainder Of Season
Laois And Westmeath Battle For Place In Leinster LGFA Decider
Alex Dunne Set For Action In Miami This Weekend
Fundraising Walk Planned For Westmeath Man Left Paralysed In Freak Accident
Shane Lowry In Action In Miami This Week
Westmeath Secure Leinster Minor Football Quarter Final
CCFL: Two Draws In Senior Division
Potential Hometown Fight On The Cards For Joe Ward
Ava O'Connor Breaks Personal Steeplechase Record
Laois Fixture In Two Weeks A "Massive Game" - Kevin O'Brien
Camross Camogie Honoured In Laois Following Historic All-Ireland Triumph
Athlone Town Secure Vital Win In Women's Premier Division
Laois And Westmeath To Clash In Leinster Camogie Decider