Two floral tributes spelling the words, 'Dad' and 'Brother' were placed on either side of the hearse that bore his coffin.
Leading the Mass at St Bartholomew's RC Church in Castlemilk, Father David Wallace drew a parallel between the care that the people of Glasgow had offered in the aftermath of the tragedy and the devotion Mr McGarrigle had shown to the three children he brought up single-handedly.
His son John, 38, was joined by sisters Marie and Linda, John Snr's sister Mary and three grand-children John, Marie and Gerry.
Mr McGarrigle, originally from Castlemilk before moving to Cumbernauld, was a regular at the Clutha for many years, and always sat in the same seat, where he performed his poetry which focused on Glasgow and its working class.
One mourner said she was certain he would have written about the tragedy, had he survived, such was his love for the Clutha.
Glasgow Lord Provost Sadie Docherty joined Glasgow MSP Humza Yousaf and representatives from the police, fire and ambulance services at the service.
Mr McGarrigle's son John walked past his father's coffin, draped in white, to read a passage from the Gospel which began, "console my people, console them".
Father Wallace said: "We welcome Glasgow City Council and the emergency services who we are very much indebted to as a city.
"I was driving home that night and sitting at the traffic lights and I was very struck by the bright lights of the Clutha Vaults.
"I didn't think that a few hours later I would be praying that people would have come to no harm.
"This was a great tragedy for nine families, for those who were inside the pub and the whole city. We were united in our grief and pain.
"It is amazing, the response from our city and around the world. People expressing their hopes for us, their consolation.
"John in his own way was a great man for care. The care of his family, bringing up his children single handedly. We re-member the care that was shown last Friday around the Clu-tha Vau-lts."
A piper played Scotland the Brave as the hearse left the church for a private service at Linn Crematorium.
The funerals of two other men who were in the pub, Mark O'Prey, 44, and Gary Arthur, 48, were held on Monday, while the funeral of the helicopter's pilot, Captain David Traill, 51, was held at Glasgow University on Saturday.
The third person to die in the helicopter was PC Kirsty Nelis, 36. Her funeral was being held today at St Andrew's Cathedral, Clyde Street, Glasgow.
Three other customers - Robert Jenkins, 61, Colin Gibson, 33, and Samuel McGhee, 56, - also died.