Kyogo Furuhashi and substitute Liel Abada had Ange Postecoglou’s side cruising to another memorable day at Hampden Park, before Daniel MacKay headed home against the run of play to hand the Championship side a lifeline with six minutes remaining.
However, Jota netted in second-half stoppage time to set the seal on yet another trophy triumph for Celtic, who had already won their 11th Premiership title in 12 years at a canter and lifted the League Cup with a 2-1 win over arch-rivals Rangers back in February.
It is the eighth time that the Hoops have won a domestic Treble, which stands as an impressive world record. Celtic have now won the Scottish Cup no fewer than 41 times, seven more than closest challengers Rangers.
It could be the last trophy they lift under Postecoglou, with Tottenham set to step up their interest in hiring the Australian as their new manager this week after he impressed chairman Daniel Levy.
“The manager’s motto is he wants us to improve every day, not to waste a training session, never mind a game. That is the reason why we have had this success,” said Celtic defender Greg Taylor.
“Some players go through their career not winning one trophy, so to win three in a season is really special.
“It says everything about the group of players, the staff and fans. It has been a collective effort.”
Asked about the ongoing speculation linking Postecoglou with Spurs, ex-Tottenham and now Celtic goalkeeper Joe Hart said: “When you are around amazing footballers and top managers, the noise is always there - but that is all it is.
“We are privileged to be on the inside and today was the focus all week, the manager made that very clear.
“Whatever happens now will (happen) - it is the world of football, full of speculation and rumour, but the facts today were we had a treble to focus on and we did it.”