The Renfrewshire town was awash with black and white last night as a special victory party was laid on just hours after the Scottish Communities League Cup victory.
County Square was packed with supporters waving flags, wearing panda hats and holding inflatable cups.
They were celebrating the fact that, for the first time in more than 25 years, their team took silverware, beating Hearts 3-2 at Hampden Park, Glasgow.
The players paraded the shining trophy – the first ever League Cup the Paisley club has won – through the town centre on an open-top bus before speaking to fans from a stage.
Supporters cheered and screamed their heroes names before joining the team and manager Danny Lennon in singing When the Saints Go Marching In.
In the crowd was Mark Caveney and his son Ben, 13, and nephew Jack, 5, all from Paisley.
Mark, 42, was 16 last time St Mirren were victorious in a big Hampden showdown when they defeated Dundee United 1-0 in Scottish Cup Final of 1987.
He said: "I've had a good cry already - but the cup experience was different this time because I got to bring the kids - it's been an amazing day."
Ben added: "It was amazing, the atmosphere in the stadium was electric."
Panda-hat-wearing Mel McKee, 62, from Paisley, said the scenes in the town centre were "panda-monium".
He added: "I was a wonderful day - absolutely fantastic."
Music pumped out of speakers next to the stage and people with their faces painted, back and white costumes and fairground rides all made for a carnival atmosphere.
Even the occasional shower could not dampen the spirits of the Buddies as they sang, chanted and danced together.
Seven-year-old David Walls, who was at the match earlier, came to the parade with mum Kirstine, 38.
He said: "It was brilliant, when they scored me and my dad were jumping up crazy."
Iona Hill, 20, of Paisley, said she was very happy with the result. She had brought her daughter Amirrah Anderson, 3, to the celebrations.
Iona said: "You don't get a better atmosphere than this."
Renfrewshire's Provost Anne Hall congratulated St Mirren and their supporters for a "wonderful" day and a "tremendous result".
She said: "The club have overcome the odds to reach the final and they showed a great belief and determination to lift the trophy.
"In the final we saw the team and thousands of fans representing Paisley and Renfrewshire with pride.
"And it was a very proud day for me as Provost to welcome the team home to take the acclaim of their community.
"It was a fantastic day and I am sure the club and the town will build on this success."
First Minister Alex Salmond also congratulated the club, saying: "I was delighted that the visiting President Joyce Banda of Malawi had the honour of presenting the trophy to the winners.
"Although as a Hearts fan I was a wee bit disappointed, it was good to see St Mirren win in a game that was a credit to both teams and a great advert for Scottish football."
Renfrewshire Council Leader Mark Macmillan said: "This is a proud day not only for St Mirren but for all Paisley.
"The club has been revived in recent years and to win a national trophy is an outstanding achievement and I offer my congratulations to Danny Lennon and his players.