Lantana features a significant subplot involving a married man's secret affair with a male prostitute. This queer relationship is central to the marital conflict and mystery, but the film maintains a neutral stance on queer identity itself. It explores the complexities of human relationships, secrecy, and infidelity, portraying characters with nuance rather than affirming or denigrating their sexual orientation.

Lantana features a transsexual character, Valerie, whose identity is revealed during a murder investigation. The film portrays her as a complex individual caught in difficult circumstances. While some characters react with initial discomfort, the narrative itself neither affirms nor denigrates her trans identity, maintaining a largely observational stance.