The 25-year-old returned home this summer after playing a season for Italian Super 10 outfit Infinito L'Aquila and he will line out for Terenure College in AIB League Division One when the new campaign begins.
A prolific schoolboy player, he starred on a Terenure College Senior Cup-winning side which helped earned him a place in the Irish Academy (2001-2004).
Altogether, he has been capped at Ireland Schoolboy level (5 caps), Ireland Under-21 (8), Ireland President XV (3), Leinster Schoolboy (5), Leinster Under-21 (3), Leinster 'A' (15) and Senior levels.
He enjoyed spells with both Clontarf FC and Terenure College RFC, where he lifted the Division Two title, in the AIB League before moving to Italy last year.
McAllister has been the backs/kicking coach for his alma mater Terenure College since 2001 at Under-10 through to Senior Cup level.
Leinster's other current Rugby Development Officers are:
Caitriona Bergin - Womenâ00s Rugby Development Officer
Debbie Clarke - Girls Schools Development Officer/Summer Camps
Derek Maybury - Midlands Area
Wayne Mitchell - North East Area
Declan Oâ00Brien - South East Area
Dan Van Zyl - Metropolitan Area