Matthew Jonathan McNamara, was raised as the son of Julia and Sean McNamara, although his biological father is Christian Troy, a man he regards as an uncle. Matt has one younger maternal half-sister, Annie and a younger maternal half-brother, Conor. Through Christian he also has a 24 year old half-sister named Emme Lowell. He is approximately 16 years of age at the beginning of the show's first season. Although he isn't as much of a ruffian in the beginning, it is implied that he was a delinquent in his early years, as Sean says to Christian, "I too many years trying to corral your bad genetics".
Matt has had a rough life as of late. This all started in Season 1 when he decided that he needed a circumcision. When his father told him that he could not get one, Matt decided to perform the operation himself. He found instructions on the internet. Once he got himself drunk on wine, he made one cut, saw the blood and passed out. Sean performed the surgery to correct it and apologized for having said no in the first place.
Also in Season 1, Matt found out that his girlfriend, Vanessa, was really a lesbian. He walked in on her kissing another cheerleader, Ridley. This led to Matt being involved in a few threesomes with the two girls. Matt became closer to Ridley and in turn Vanessa was crushed, as she had real feelings for Ridley. Matt was enjoying this until his mother walked into his room and found him in bed with the two girls.
Matt recovered from losing his girlfriend and tried to live a normal life. All was going well until he and his friend Henry got in a hit-and-run accident. They had been smoking marijuana and then were driving home and accidentally hit a classmate. They fled the scene, leaving her critically injured.
In Season 2, Sean and Julia decided to hire a life-coach to help Matt boost his self-esteem. They employed the services of Ava Moore. Matt began to have a sexual relationship with Ava and he fell deeply in love with her. The relationship tore him apart from his family. Matt was devastated when she left the country and him behind. He was even more devastated when he found out that Ava was transgender. This caused him to have many doubts and worries about his sexuality.
Matt decided to go to a trans nightclub, where he was hit on by Cherry Peck, a trans woman. Cherry took Matt home with her and they began to get intimate. Matt became infuriated upon finding out that she was pre-op, and beat Cherry very badly. He then went home and shaved his head. Matt had fallen deeper and was becoming a different person.
A few days later, Cherry and a group of her transgender friends found Matt and got their revenge on him. They badly beat him and urinated on him. Cherry then went to McNamara/Troy and tried to bribe Sean into doing an operation to correct the facial injuries that Matt had given her. Sean threatened to sue and kicked Cherry out. However, Matt went to his father and convinced him to do the reconstructive surgery for free. He felt awful about what he had done to Cherry and wanted to make things right. This caused Matt and Cherry to develop a friendship.
Also in Season 3, Matt began dating Ariel Alderman. At first she seemed like a pretty, sweet, innocent girl. However, it turned out she was anything but. Ariel is a very racist person who makes Matt turn into a racist. Matt goes to dinner at her house and befriends her father, Mr. Alderman. He is even more racist than his daughter. Mr. Alderman convinces Matt to steal files from McNamara/Troy so that he can use them to get insurance companies to stop paying for surgeries that alter (or in his opinion, hide) natural ethnic features.
Matt eventually breaks up with Ariel, as he realizes that she and her father are not good people. When Ariel and Mr. Alderman spot Matt and Cherry in the mall, things take a horrible turn for the worse. Mr. Alderman kidnaps Matt and Cherry and ties them to chairs in his garage. He holds a gun to them and makes Matt cut off Cherry's penis. Matt does not want to, but Cherry tells him to do it. Matt feels awful but cuts it off anyway. Mr. Alderman puts the two of them back in the car and drives them out into the forest. He gives Cherry a shovel and makes her dig a grave. The whole time he is holding a gun to Matt's head. Matt becomes enraged and refuses to play these games anymore. He puts the gun to his own head and yells at Mr.Alderman to pull the trigger. Mr. Alderman freezes and can't do it. Meanwhile, Cherry takes the shovel and blindsides Mr. Alderman, striking him in the head. Cherry picks up the gun and Matt tells her to shoot him. The gun is fired and the next we know of Matt is that he has returned home that night. There are many questions involving Matt that will be answered in Season 4.
In Season 4, Matt runs into Kimber Henry at the gym, and learns about her religion of Scientology. Matt converts, only in the hopes of sleeping with her. Kimber encourages Matt to move out of the McNamara home due to it being "toxic", and ends up cleaning roadsides as part of his religious training. After being rejected by Christian, Kimber tries to get back at him by sleeping with Matt. Several weeks later, Matt and Kimber tell Sean and Christian that they are married and expecting a baby. The couple move in together and Matt films a porn movie with her in an effort to spice up their sex life. Matt confesses to Sean that he knows Kimber only married him to get back at Christian, but he really does love her.
In Season 5, Matt shows up in Los Angeles with newborn baby Jenna. He claims that he is now poor because Kimber gave all their money to Scientology, and that he has left her. In truth, this is nothing but a ruse to get money to pay for his and Kimber's spiraling addiction to crystal meth. Kimber tries to return to the porn industry, but is shot down by producer Ram Peters due to her habit. He does, however, want Matt in a gay porn movie after seeing the size of his penis in the homemade porn movie they made last year. Matt is willing to do the movie, until Kimber stops him. After quitting drugs through Scientology, Kimber agrees to dump Matt in return for surgery on her meth-ravaged face and teeth. Kimber tells Matt that she never loved him and moves in with Ram, taking Jenna with her. Devastated, Matt turns to meth and accidentally blows up the motel he is staying in, inflicting severe burns on his body. While resting in hospital, Matt bonds with his burns counselor, Rachel Ben Natan, who was left horrifically scarred when a terrorist in her native Israel blew up right next to her. Matt and Rachel start dating, until Rachel ends things as she cannot see a future with him. Matt yells at her for daring to be "picky", and that she should consider herself lucky to be with him. Matt meets one of Christian's patients, Southern girl Emme Lowell, and sleeps with her. Matt and Emme feel a connection like none they've ever felt before. This is explained when Emme reveals that she came to Los Angeles to find her biological father: Christian Troy. Matt and Emme come clean to their parents about their love, and are told to end things immediately. Emme plans to return home; despite his feelings, Matt makes the right decision and lets her go, finally maturing.
In the episode Conor McNamara 2026, later retconned, Matt was shown to have become a successful plastic surgeon and to have carried out an operation on his half-brother Conor to fix his hands. Kimber and his daughter were neither seen nor mentioned.
- Erica Noughton (maternal grandmother)
- unnamed maternal grandfather
- Tom McNamara (legal paternal grandfather)
- Kathleen McNamara (legal paternal grandmother)
- Gail Pollack (biological paternal grandmother)
- unknown rapist (biological paternal grandfather)
- Brendan McNamara (legal paternal uncle)
- Max Pollack (biological paternal half-uncle)
- Sarah Pollack (biological paternal half-aunt)
- Julia McNamara (mother)
- Sean McNamara (legal father)
- Christian Troy (biological father)
- Annie McNamara (maternal half-sister)
- Conor McNamara (maternal half-brother)
- Emme Lowell (paternal half-sister; lover)
- Wilbur Troy/Gabriel Sutherland (adoptive half-brother; Christian's adopted son)
- Raphael McNamara (adoptive half-brother; Sean's adoptive son)
- Kimber Henry (ex-wife; step-mother)
- Jenna McNamara (daughter)