He replaces Denis Leamy.
Sean O'Brien will become Leinster's new contact skills coach, following the departure of Denis Leamy.
O'Brien will return to the province having brought an end to his playing career at London Irish in recent weeks.
Leamy is leaving the eastern province to return to Munster.
He'll fulfill the role of defence coach as part of Graham Rowntree's coaching ticket.

Friday Morning Sports Update
Munster Make Ten Changes To Their Team For Saturday's Game Against Exeter
Manchester United Aim To Clear €1.4 Million A Week From Wage Bill For Future Signings
Suncroft's Cian Prendergast Returns To Captain Connacht In Tomorrow's Game Against Sharks
Thursday Morning Sports Update
Kildare U20 Football Team & Panel vs Offaly
Wednesday Morning Sport Update
New Report Shows Growing Pressure On Volunteers At GAA Club