John Gannon was born in Riverview to Edward and Christine Gannon. Since his family descends from royal blood, he used to mingle with people of the higher layers of society and received an education set to get him a high paying job. John had a happy childhood and was very popular in the town.
When he turned into a teen, he usually went out with his friends and hung out in The Gazebo. One day, he was there with his friends and met a tourist girl called Mary. They quickly fell in love and stayed together during the whole summer, but had to go their separate ways when her family returned to Twinbrook.
They kept in touch after she returned home and they were keeping their long-distance relationship in good shape. However, John overheard his parents talking about sending him to a boarding school. So, upon realising he wouldn't be able to keep in touch with her that often, he went to Twinbrook and took her to her prom. After that, he left to the Smuggsworth Prep School.
When he graduated, John came home with a girl he met while in his boarding school, Rachel. They were getting along just fine and John had forgotten about Mary. One day, after a night of hitting the bars, Rachel put the moves on John, who went along with it.
A couple of weeks later, Mary grew up and moved to Riverview, when John realised he had made a mistake by sleeping with Rachel. He broke up with the latter and she told him, before she moved away, that she was pregnant. John, however, went back to Mary.
He got a job in the Business career (just like the rest of his family) and got engaged to Mary. They married shortly after in a ceremony by the river. She moved in with him and had a healthy and happy marriage - they engaged in several activities together, such as having picnics, cycling, fishing, swimming, among others. However, their relationship got strained when she got pregnant.
John received a call from Rachel, telling him that their daughter had been born a couple of days before. John was upset, because the little girl would probably never meet his father - so he took care of Mary's every need and, nine months later, their son was born. John wanted him to continue the family tradition of businessmen, while Mary showered him in love and gifts, even bringing a Siberian Husky home from the kennel.
The things got even worse when Mary's mother died and her father and her brother moved in - only to cause more trouble with Jake.
John and Mary's marriage was very strained after her family's arrival in the Gannon Manor, since everyone wanted to raise Jake in a different way. One day, John got a call from Rachel, who told him that she was moving to Riverview and wanted him to pay the child support pension. So, after a big fight with Mary regarding Jake, he hired an actor to pretend he was a marriage counselor and to recommend moving somewhere else. So, John, Mary, Jake and Charles moved to Bridgeport.
Their marriage was starting to fix itself over time, since Rachel couldn't trace them and Jake was growing up, with his personality almost formed. When Jake turned 15, the Gannons went to the Prosper Room to celebrate. On their way out, they faced a mysterious man trying to assault them. John tried to fight the criminal, but he killed him. Then, while trying to protect her son, Mary died at gunpoint as well.
- Although he didn't show it very often, John was a Jacoban, being one of the only Gannons in his generation to not be agnostic.
- His signature vehicle was a dark grey-blue Requiescence.
- He mastered his charisma skill.
- He completed his lifetime wish.