•
William H. Macy as
Frank Gallagher, the patriarch of the Gallagher family and father to Fiona, Lip, Ian, Carl, Debbie and Liam. He's an alcoholic and chronically unemployed; instead, he makes money through various scams. He's a narcissist who cares only about his next drink or drugs, often endangering or abandoning his children to fulfill his own needs. Despite being egocentric, Frank does love his children and at times proves himself a better parent than their mother, Monica. •
Emmy Rossum as
Fiona Gallagher, the feisty, street-smart eldest Gallagher sibling, who raises the children on her own due to Frank and Monica's neglect and eventually becomes their legal guardian in season 3. She struggles with addiction, impulsive behavior and self-destructive tendencies. (seasons 1–9) •
Justin Chatwin as
Steve Wilton / Jimmy Lishman, a car thief who is the love interest of Fiona for the first three seasons. (seasons 1–3; special guest star seasons 4–5) •
Jeremy Allen White as
Philip "Lip" Gallagher, the second oldest Gallagher child, who is highly intelligent, and he also takes care of the parental duties. Like his father, he suffers from alcohol addiction in the later seasons. Unlike his father, he becomes sober. In season 10, he becomes a father and is a motorcycle repairman. •
Cameron Monaghan as
Ian Gallagher, the third oldest Gallagher child. Strong-hearted, persistent, and goofy, he is gay and engages in an on-and-off relationship with Mickey, whom he later marries in season 10. In season 1, it's revealed that he's not Frank's son and Monica had an affair with one of Frank's brothers. Like his mother Monica, he struggles with
bipolar disorder. •
Emma Kenney as
Debbie Gallagher, the fourth Gallagher child and youngest daughter, who becomes a mother to her daughter, Franny, named after Frank, at age 15. She later comes out as a lesbian and dates Sandy Milkovich, the cousin to Mandy and Mickey. She displays extreme abandonment issues due to her parents' treatment which causes her to be clingy and erratic with her romantic relationships. As an adult, she becomes a freelance welder. •
Ethan Cutkosky as
Carl Gallagher, the fifth Gallagher child, who has a tendency for troublemaking as a child, and goes to juvenile prison as a teenager. But he grows up to be a policeman after witnessing a murder and wanting to help the poor. • Christian Isaiah as
Liam Gallagher, the mixed-race youngest Gallagher child whose true parentage is ambiguous. As the youngest child, his care is a key priority for his older siblings throughout the series. (seasons 9–11; recurring season 8) (His role has been recast three times. In seasons 1–2, he's played by twins, Blake and Brennan Johnson. In seasons 3–7, he's played by twins, Brenden and Brandon Sims. From season 8 and onward, he's played by Christian Isaiah) •
Shanola Hampton as
Veronica "V" Fisher, Fiona's best friend and neighbor, who lives with her husband Kevin and, later, their twin daughters. She and Kevin often help out the Gallaghers, being their only real adult role models. •
Steve Howey as
Kevin "Kev" Ball, Veronica's husband and the owner of the series' main and local bar The Alibi Room. He comes from a rough childhood as he was in the foster care system for the majority of his childhood life but has an eccentric personality and is always goofy. •
Noel Fisher as
Mickey Milkovich, a violent and erratic member of the Milkovich family, who are neighbors of the Gallaghers. He is Ian's main love interest and later husband who eventually becomes estranged from his family due to their homophobic and
white supremacist attitudes. He has an ex-wife, Svetlana, whom he was forced to marry by his homophobic father (seasons 3–5, 10–11; recurring seasons 1–2; special guest star seasons 6–7, 9). They have a son named Yevgeny. •
Joan Cusack as
Sheila Jackson, mother to Karen and love interest to Frank for the first five seasons. She is a sex addict seeking dominance over men and suffers from agoraphobia which prevents her leaving the house in the earlier seasons. She leaves Chicago in an RV at the end of season five. (special guest star seasons 1–5) •
Laura Slade Wiggins as
Karen Jackson, Sheila's rebellious and destructive daughter and an early love interest for Lip. She later gets hit by a car that was driven by Mandy, which leaves her to be permanently brain damaged, and decides to move with her much older ex-husband Jody to seek treatment in Arizona. (seasons 1–2; recurring season 3) •
Zach McGowan as
Jody Silverman, Karen's husband and adoptive father to her son, who later becomes a love interest to Sheila before reuniting with Karen and moving away. (season 3; recurring season 2) •
Emma Greenwell as
Mandy Milkovich, the sister of Mickey, love interest of Lip, and best friend of Ian, whom she pretends to date in season one to hide the fact he is gay. She eventually leaves to escape her physically abusive boyfriend. She later returns to come back as an escort. (seasons 3–4; recurring season 2; guest season 5; special guest season 6) (
Jane Levy played Mandy for six episodes of season 1) •
Jake McDorman as
Mike Pratt, Fiona's boss and love interest. (season 4; recurring season 3) •
Emily Bergl as
Sammi Slott, the needy and manipulative elder half-sister of the Gallaghers, who is revealed in season 4 to be a product of a teen romance of Frank's. She is the mother to Chuck. (season 5; special guest season 4) •
Isidora Goreshter as
Svetlana Yevgenivna, a Russian émigré who is Mickey's wife and the mother of his child. She later divorces him and engages in a throuple with Kevin and Veronica while working at their bar. (seasons 7–8; recurring seasons 3–6) •
Richard Flood as
Ford Kellogg, an Irish carpenter and love interest to Fiona. (season 9; special guest season 8) •
Kate Miner as
Tami Tamietti, a hairdresser from a middle-class background who is Lip's love interest and later mother to his child. (seasons 10–11; recurring season 9) ==Episodes==