The Dublin forward had his one match ban overturned by the Disputes Resolution Authority in the small hours of this morning.
Their judgement cited a “lack of fair procedure” at an early stage of the GAA's internal disciplinary process.
Connolly was shown a red card by referee Joe McQuillan last Sunday for striking Mayo's Lee Keegan.
Throw-in in today's replay is at 5.
Dublin's Ladies footballers are also in semi final action today – they face Armagh at Parnell Park, with Cork awaiting the winners in the final.
That one's underway at 2.
