John Duffy is a retired English born Scottish international rugby league player. John Duffy's position of choice was Scrum-half/Halfback and he also operated as a Stand-off/Five-eighth, and Hooker.
He played for Leigh, Salford and Warrington in the European Super League and also played for Whitehaven.
Duffy is a Scotland international.
Duffy became Super League's youngest debutant when he made his Warrington debut at the age of 16.
He was named in the Scotland squad for the 2008 Rugby League World Cup,  and was part of the coaching staff for their 2013 Rugby League World Cup campaign. 
In June 2014 he was appointed head coach of Swinton in the wake of Lions' player coach Ian Watson's departure to become Salford's assistant coach.