Relatives
Tracy Quartermaine (mother)
Paul Hornsby (father)
Jenny Eckert (step-mother)
Edward Quartermaine (maternal grandfather)
Lila Quartermaine (maternal grandmother)
Ida Zemlock Quartermaine (great-grandmother; Deceased)
George Quartermaine (great-grandfather; Deceased)
Susan Hornsby (half-sister)
Ned Ashton (half-brother)
Alan Quartermaine (uncle)
Monica Quartermaine (aunt)
Bradley Ward (uncle; Deceased)
Jimmy Lee Holt (uncle)
Brooke Lynn Ashton (niece)
Justus Ward (cousin)
Alan "AJ" Quartermaine Jr. (cousin)
Jason Morgan (cousin)
Emily Bowen-Quartermaine (adopted cousin)
Chloe Morgan (distant cousin; Deceased)
Alexandria Quartermaine (distant cousin; Deceased)
Celia Quartermaine (distant cousin)
Flings & Affairs
Georgie Jones (dating)
Faith Rosco (kissed)
Sage Alcazar (lover)

Dillon's parents are Tracy Quartermaine and Paul Hornsby. After spending most of his life traveling in Europe with his mother, he came back to Port Charles when Tracy dropped him off to stay with the Quartermaine's while she continued to travel. His first week was an interesting one when Georgie Jones kissed him in the middle of Kelly's to make her sister Maxie think she had a boyfriend. After the initial awkwardness of the situation, Georgie and Dillon soon fell in love. She discovered his love for movies and couldn't resist his quirky sense of humor.

Mac never liked the idea of Georgie being with Dillon, he did everything to keep them apart. Dillon continued to get himself into trouble, so Edward threatened to send him away to Military school. Dillon and Georgie decide to try to run away together. But Maxie was forced to tell Mac where they were and he busted them again.

Lorenzo Alcazar offered to pay Dillon to do some errands for him. He even was seduced by Faith in her attempt to steal money that he was transporting for Alcazar. When Alcazar's niece Sage came into town, he hired Dillon to be her babysitter. Dillon was forced to take Sage out of the country for her safety where Sage ended up getting Dillon thrown in prison.

Georgie teamed up with Dillon's mother Tracy to stop Dillon from working for Alcazar. Tracy agreed to force Dillon to quit his job if Georgie broke up with Dillon. Of course Georgie was devastated, but happy that Dillon was safe. A heartbroken Dillon expressed his sadness by losing his virginity to Sage. Georgie walked in on them and they broke up for good.

To make Dillon jealous, Georgie created a fake boyfriend and pretended she was in love with another guy. Dillon was upset but he continued to see Sage. Dillon, Sage, Georgie, and her fake boyfriend, Tom all got caught in the Port Charles Hotel fire where Georgie told Dillon the truth about her lies. They decided they still loved each other and they got back together.

Tracy attempted to bribe Dillon to get his vote to allow her to become the CEO of ELQ.

Dillon and Georgie wanted to make love so they went to the Quartermaine boathouse for privacy. But when they got there, they found a dead body. This of course put a crimp in their plans.

Ned asked Dillon to work at L&B and assigned him to direct a video with an up and coming young talent named Ashley B. Dillon of course had his own ideas about what he wanted the video to look like, but Ashley insisted on putting her two cents in. Georgie did a good job of acting as the mediator.

While working at L&B, Dillon began to hear a mysterious young woman singing with a beautiful voice. He told Georgie about the voice and they decided they wanted to use this girl to prove to Ned that Dillon had the ability to find talented people for the company. When they confronted Lynn, they found out she had run away from her overbearing stage mother and had no desire to capitalize on her talent.

When Lynn's mother sent a private detective to find her daughter and bring her home, Dillon ended up escaping from him with Lynn. While hiding out with her, he found out she was actually his cousin, Brooke Lynn.