Ian Gallagher
Gender	Male
Portrayed By	Cameron Monaghan
Season	1 - Present
Partners	Kash Mickey Milkovich Mandy Milkovich (beard)
Parents	Frank Gallagher (de jure) Monica Clayton (assumed biological)
Siblings	Fiona (half) Lip (half) Debbie (half) Carl (half) Liam (half)
Sexual Orientation	Homosexual

Ian Clayton Gallagher is the third Gallagher child. He's in Army ROTC at school and works at a local convenience store. He is gay and, as the series begins, is having a secret affair with his married boss, Kash, which his brother Lip discovers shortly after finding out that Ian is gay. Kash's dominating wife also discovers the affair and, although angry, she tells Kash he can continue sleeping with Ian after Kash gets her pregnant again as a quid pro quo. She allows Ian to keep his job but strictly forbids any sexual encounters between the two until she successfully conceives. 

A girl in Ian's class, Mandy Milkovich, becomes sexually interested in him and becomes enraged when he doesn't reciprocate the attraction. For revenge, she tells her family that Ian sexually assualted her, causing her brothers to chase him with violent intentions for a few days. In desperation, Ian eventually reveals to Mandy that he's gay, after which she not only calls off her brothers but also offers to pretetnd to be his girlfriend, giving him a cover story. The two start going on non-sexual dates, genuinely enjoying each other's company.

Ironcially, Ian later begins a secret affair with Mandy's brother Mickey, who is a neighborhood thug and frequently terrorizes Kash, flagrantly shoplifting from his store. When Kash discovers the affair, he goes into a jealous rage and, the next time Mickey steals merchandise from him, (consisting of just a candy bar in this case), Kash shoots Mickey in the leg and has him arrested for theft.

During Season 1 it is discovered that Ian is not Frank's child but that of one of Frank's brothers. Ian and Lip investigate by visiting two of Frank's brothers, and they both come to believe Ian's father is Clayton Gallagher , whom Ian strongly resembles and whose given name matches Ian's middle name. Clayton's wife becomes very upset looking at the two sitting side-by-side and tells Clayton that Ian looks like one of her own sons and that she wants Ian and Lip out of her house. Ian decides not to interfere with Clayton's marriage, as his place is with the family he's always known.

During Season 2, Ian and Mickey resume their secret sexual encounters after Mickey's release on parole. One day Frank walks in on them having sex at the store and makes a few sarcastic comments. Mickey, horrified at the possibility of being revealed as gay, decides to kill Frank to protect his secret. Ian tries to talk Mickey out of the murder but fails; however, at the last minute Mickey is unable to go through with the deed and assaults a police officer, deliberately violating his parole and returning to prison. 

Mandy is later revealed to be pregnant. Since Ian has been posing as her boyfriend, Mandy's father, Terry, assumes him to be the father.  Enraged, Terry assaults Ian at the Gallaghers' house and, after being stopped by Ian's mother, vows further violence against Ian. Ian hides out from Terry for several days, during which time he goes to a hotel with an older man he had recently met, Dr. Lloyd, for sex. Eventually, Ian and Lip decide to get rid of Terry by planting an illegal gun in his possession. However, Terry catches them and chases them, cornering Ian in the kitchen, pointing a gun at his head, and threatening to kill him. Mandy arrives just in time, aiming a shotgun at her father and revealing that he, Terry, was the father of her unborn child, not Ian or Lip. Ian and Lip are disgusted at learning Mandy has been subject to incest, but Mandy warns them that if they say anything she'll kill them herself.

Sometime later, Ian is invited along to meet Jimmy's family at a seafood restaurant. However, Jimmy's introduction of his father was entirely unnecessary as he was revealed to be Dr. Lloyd! A shocked Ian excuses himself to go to the bathroom and is quickly joined by Dr. Lloyd. Ian asks if the doctor's family members are aware of his sexuality, but he claims not to be gay. Seeking comfort, Ian tries to tell Fiona about Dr. Lloyd but is unable to work up the courage.

During Season 3 Ian is still dating Dr L. and having sex with another guy from his ROTC class, when Mickey shows up again. After Ian is interrupted, the boy pleads with Ian not to tell anyone, then Mickey slightly beat the boy up and the boy runs off. Mickey and Ian have sex and then start catching up from an interval of seperation. Ian later asks Mandy for some advice about knowing whether or not if a guy is attracted to you, specifically, Mickey, though he doesn't let her know thats who he is talking about. Mandy says that he would know it when he looks in his eyes. The next day Ian saves a kid from Mickey's wrath. Ian then tries to stare at Mickey's eyes, seeing if their was the supposed "look", but Mickey only asked what he was looking at.

Mickey is becoming  jealous due to the fact that Ian is seing other men, namely Dr L. Eventually, Dr. L. reveals that he is gay when he was kicked out of his house and called Jimmy soon after. Dr. L and Jimmy meet at the Alibi and Dr. L. explains the situation and is still discreet about why he was possibly thrown out, likely due to Candace (Jimmy's mother) finding out about Dr. L.'s sexual orientation. When Dr. L. and Jimmy come back to the Gallagher house, Dr L seems to want to reach for Iam, but he falls down because he's so drunk. Jimmy doesn't want his father out drunk, so offers to let him sleep on the couch. Dr. L. wakes up in the middle of the night and  decides to look for Ian upstairs with nothing but his trunks on. He runs into Molly (Mandy's sister) while peeing in the bathroom. He apologizes and then continues walking down the hall. He stumbles upon Lip. Believing that it's Ian, Dr. L. climbs into the bed with no clothes on. Lip reacts absurdly, saying that Dr. L had a boner and almost beats him up until Fiona walks in to intervene. Dr. L. looks around and then says he was looking for the bathrom because he was going take a shower, trying to hide the fact that he was looking for Ian. Jimmy takes his dad downstairs and Fiona asks Lip if he was sure Dr L had a boner trying to get in bed with him, until Ian admitted that Dr L was looking for him. Ian also admitted that he was dating Jimmy's dad, and that he didn't know at the time when he met him at a club. After a brief conversation with Jimmy downstairs, a car comes to take Dr.L home.

Dr L later enlists Ian for help getting his things back from his wife Candace, saying he can take anything he wants as everything in the house is covered by insurance, but to make sure to get a few of his choice belongings. He explains a good time to rob his own home, since Candace likes to excercise at a certain time of day and is almost always in bed till noon because of late nights spent drinking vodka. He tells Ian to show up in the early morning, with a van to make it look like they might be movers. Ian agrees, and asks Mickey if he wants to help. Mickey agrees. The morning of the robbery, Ian tells Mickey that he's not afraid to kiss him, even though Mickey is, not wanting to put his homosexuality on display. However Mickey, as he gets ready to go into the house, kisses Ian quickly, then rushes off. Ian waits in the van to be the getaway driver until the robbery goes wrong. Candace wakes up when she hears a ruckus and comes down the stairs with a shotgun in hand. She ends up shooting Mickey in the butt. Ian quickly drives away with a bleeding Mickey and his cousins. He ends up calling Dr. L and asks for his help in getting Mickey mended.

Ian and Mickey continue their sexual relations. One day, while at Mickey's house for a sexual encounter, Ian and Mickey are caught by Mickey's dad, Terry. He goes after Ian, saying Mandy wasn't enough, and punches him. Mickey jumps on Terry to get him off Ian. Terry overpowers Mickey and beats him with the base of his gun. Ian tries to make a run for it, but Terry points a gun at him and forces him to sit on the couch. Mickey tries to stop Terry despite that fact that he bleeding. Terry knocks Mickey out cold with a swift punch to the face. Thinking he can also knock the gay out of his son, he calls a Russian prostitute over to have sex with Mickey and forces Ian to watch. Ian later tries to speak with Mickey and is unsuccessful. He then finds out from Mandy that Mickey is getting married, to the Russian prostitute, since Mickey knocked her up. Ian tries to find out more by going to Mickey who only calls him Gallagher after Ian breaks a bottle. Ian tries to provoke Mickey into punching him and he does. Then again and Ian could only say that Mickey loved him. Ian then tries to provoke again and then lays on the ground asking him if he feels better. Mickey delivers a kick almost knocking out one of Ian's teeth. Mickey left saying that he felt better. At the end of the episode after Frank is thought to be gay in his own world, Ian cries alone in his room.

It's the day of Mickey's wedding, and Ian helps Mandy set up the chairs. Ian is still so bothered by the fact that his gay lover is getting married to a woman that he starts to drink heavily, making him very drunk just before the wedding. He tries to confront Mickey again, pleading with him not to go through with it. Mickey says it's only a piece of paper, but Ian doesn't believe so. The two have sex and then Ian tries again to stop him from going through with the wedding. Mandy walks in, asking what's going on, saying the wedding is about to start and questioning Ian's presence there because she thought Ian had left. Ian replies that it was a last minute desicion he made to stay. Mickey proceeds with the wedding. Ian continues to drink more achoholic beverages. Eventually he is so drunk and after Lip walks in and breaks up with Mandy, Ian tries to call out Mickey and his whore, but Lip asked what he was doing there, thinking Ian didn't want to be at the wedding at all. Lip tries to take Ian home, with Ian stumbling along the way, throwing up, and eventually laying down and passing out in some bushes.

In the last episode of Season 3, Ian goes to enlist in the army, and gathers all the documents he needs, along with Lip's ID because Ian is not old enough to enlist yet and Lip is. He visits Mandy and Mickey, and asks Mandy to get him something. Mickey tries to breifly talk to Ian. Ian tells him that he's enlisting and Mickey almost tries to persuade him not to, but doesn't come up to the courage of saying it. Mandy gives Ian something and he leaves. Mandy asks Mickey if that's all he can say. Mickey turns around and looks at her. She then calls him a pussy, and walks away. This would indicate that Mandy knows about Ian and Mickey. Ian makes his fake ID and gets on a bus as the officer refers to him as Lip Gallagher.