The 46-year-old from Newton Mearns is taking part in a charity, white-collar boxing match in Glasgow next month to raise money for the Royal Hospital for Sick Children (Yorkhill) and the Beatson West of Scotland Cancer Centre .
One of the most accomplished boxers Scotland has ever produced, Jacobs won British, Commonwealth and European titles and challenged American superstar Pernell "Sweet Pea" Whitaker for his WBC world title in 1994 when Whitaker was the best pound-for-pound fighter in the world, losing by decision.
On Saturday, October 6, he will face Craig Millard from Edinburgh at the Crowne Plaza Hotel in Glasgow as part of the Fortune Favours the Bold event, organised by SK Boxing Promotions.
Jacobs, known as "The Kid", said: "I've not pulled the gloves on since 1997. I was tempted after going along to an SK Boxing Promotions fight night and seeing all these up-and-coming young boxers.
"Gyms are so different now to the spit-and-sawdust places I trained in and the young guys these days are very well looked after. If my name on the card can attract some people along and maybe get some new people into boxing, then that will be great.
"I also want to raise money for Yorkhill and the Beatson. My wife Linda had breast cancer last year. She is fine now but I wanted to do something for the Beatson."
Jacobs is also promoting his forthcoming autobiography which will be in the shops by Christmas.
"My book will tell all about my career and the ups and down I've experienced since I retired," he says.
"I got involved in some silly things when I retired but I came back from it and I think I have an interesting story to tell.
"I think it's great that you can put your life story in a book and not too many people have had a life which would allow them to do that.
"It's not just a book about being at the top.
"There was a stage in my life, around 1990, when I had been knocked out in a fight and all the newspapers had written me off.
"I was out of the ring for a good few years and had to fight my way back."
Jacobs, who now runs a property maintenance firm, was a huge fan favourite when he fought and, proud of his Jewish roots, wore a Star of David on his fight shorts.
He joked: "It helped that I was Jewish in the west of Scotland, because both Catholics and Protestants supported me, although I did sometimes get asked whether I was a Catholic Jew or a Protestant Jew.
"I'm proud of my heritage. My children are Jewish and it's a big part of my life.
"This show next month is about more than the book.
"Hopefully, the show will inspire some youngsters to take up boxing and go along to gyms like Glasgow Fitness in Thornliebank where I am training for this fight.
"Combat sports are all about discipline and it's a great thing for young people to get involved in.
"Kids who go out and fight in the street will never get anywhere.
"People who train in boxing, mixed martial arts or any combat sport have something about them that comes from being part of a gym family.
"It's a brilliant way to improve yourself on every level."
Glasgow Fitness gym is run by Raj Singh, an accomplished Muay Thai and kickboxing coach who first got into combat sports under Jacobs's guidance.
Gary Jacobs Health and Fitness on the South Side of Glasgow was opened after his boxing career ended, and Raj – then a 16-year-old – lived nearby.
Raj said: "I went along and fell in love with the place.
"There was a real feeling of family in the place and that's the model I used when I decided to start my own gym.
"The people there have become lifelong friends.
"At Glasgow Fitness, our fighters and students are coached in a way that makes sure they are not put into any situation where they are out of their depth but also pushes them to improve and learn.
"We're thrilled to have Gary training with us for his fight."
Although his gym eventually closed down, Jacobs is proud of what he achieved there.
He said: "It was a different kind of gym.
"I didn't want to even try to compete with the big chain gyms. I wanted there to be more of a focus on each individual."
Jacobs's opponent at Fortune Favours the Bold, Craig Millard, is a vastly experienced amateur boxer.
Promoter Sam Kynoch says it is a match-up between two men of similar ages who both had successful careers, but at different levels.
Sam said: "Obviously Gary fought at a higher level but Craig has been active for a long, long time and is in great shape.
"It will be an interesting fight and there are plenty of other excellent match-ups on the card too.
"It's great to have Gary involved. He has been in the ring with some of the best fighters in the world and went the distance with them."
As well as Jacob's fight and a host of other matches, there will be a four-man super-middleweight tournament featuring Glasgow's Marc Kerr and Bothwell's Stevie White. Other boxers such as undefeated heavyweight John Stevens (14 wins) will also feature.
The event on October 6 includes a drinks reception and three-course meal, with tickets costing £60 and £70 still available from www.sk-promotions.co.uk