Now the 40-year-old is desperate to see an end to Hibs’ infamous despair in the tournament – even if it means ditching a lifetime of loyalties to cheer his former club to victory over boyhood heroes Celtic.
O’Neil was in the last Easter Road team to reach the final when, in 2001, they lost 3-0 to Celtic.
The Parkhead men, who face Hearts on Sunday, could again stand in the way if Pat Fenlon’s side can see off Aberdeen in Saturday’s semi-final.
But O’Neil would love to see silverware returning to Leith next month – and he hopes the current Hibs team are aware of how big an opportunity they have to become legends.
He said: “I was brought up a Celtic fan but I would love to see Hibs win the cup, even if it was a Hibs v Celtic final. That’s what the pressure means to ex-Hibs people, Hibs fans and current players. I just hope the Hibs players realise how big this is.”