London-based Duffy is group president, Europe, of the Polo Ralph Lauren Corporation.
He joined Polo Ralph Lauren Corporation in 2003 as president and chief operating officer, Europe, from the Sara Lee Corporation where he held a number of senior posts.
Chairman Dr John Reid said: “We will be drawing upon his enormous experience in UK and international retail operations, merchandising and brand development as we look to build our business further in the coming years.”
Duffy added: “I was brought up in Glasgow, and as a lifelong supporter of the club I am honoured to join the board.” Duffy will be one of eight board directors. Irish businessman Dermot Desmond owns 39 per cent of the voting shares in Celtic.