Last Tango in Halifax features a central lesbian relationship between Caroline and Kate, depicted with dignity, complexity, and normalcy. The narrative consistently affirms the worth of LGBTQ+ lives and love, portraying their relationship and Caroline's identity with respect and empathy, even through tragic events.

The series portrays Christianity primarily through Celia, whose traditional values, sometimes leading to prejudice, are shown as something she must overcome. The narrative critiques her judgmentalism rather than the faith itself, ultimately depicting her growth and acceptance positively, aligning with the idea that bigotry, even when framed by religious belief, is wrong.