Donald Joseph O'Riordan (born 14 May 1957) is an Irish football coach and former professional player, who is the manager of Women's National League club Treaty United. O'Riordan notably played for Middlesbrough, Grimsby Town and Notts County amongst others and has previously been on the coaching staff at Sheffield United, in the role of technical director/coach of their feeder club Chengdu Blades F.C. in China.