Shameless features prominent LGBTQ+ characters, notably Ian Gallagher and Mickey Milkovich, whose extensive arcs depict their identities with dignity and complexity. Despite facing significant external prejudice and personal struggles, their journeys ultimately affirm queer love, acceptance, and resilience within the show's gritty, realistic setting.

Shameless features Trevor, a trans man, as a significant and positively portrayed character. He is depicted with dignity, complexity, and agency as a social worker and a love interest for Ian. The narrative respectfully addresses his identity, using it to foster growth in other characters and highlight his commitment to the LGBTQ+ community.

The US adaptation of Shameless features multiple instances of race swapping. Notably, the characters of Veronica and Liam, who were depicted as white in the original UK series, are portrayed by Black actors in the American version.

The show frequently satirizes Christian institutions and the hypocrisy of some adherents, particularly through Frank Gallagher's schemes to exploit churches for personal gain. While individual characters may hold faith, the narrative consistently highlights the problematic aspects of organized religion and its exploitation.