Sheen (70) will host a full public interview at the Town Hall Theatre as well as debuting his own movie, Stella Days, which also features Amy Huberman.
The west of Ireland festival has been selected as the venue for the world premiere of Sheen's new movie about a local cinema in an Irish town.
The father of embattled Two And A Half Men actor Charlie Sheen takes on the role of a parish priest whose dedication to cinema drives him to set up a local movie theatre in the town.
However, he faces stiff opposition from locals, who question his faith, and some who believe the funds could be better spent.
Ireland rugby captain Brian O'Driscoll's wife Amy joins the stellar line-up, which includes Stephen Rea and Marcella Plunkett.
The small village of Fethard, in Tipperary, was transformed for the three weeks of filming late last year.
Sheen said: "I love this town, I love Ireland. I love the culture, the people, so I'm happy as Larry."
The star previously spent time in Galway when he spent a semester as an international student at the National University of Ireland.
He studied a selection of English literature, philosophy and oceanography during the 15- week semester.
The 23rd Galway Film Fleadh opens on Tuesday, July 5, with the Irish premiere of Parked.
The full programme for the festival will be launched in the Radisson Hotel on June 21.