This study aimed to explore the relationships between being an 'affected other' (AO) due to another person’s gambling and health risk behaviours (e.g., poor diet), financial problems, general health, and mental wellbeing. Being an AO was defined as having a partner or relative who gambled regularly in the past 12 months. Compared to people who were not AOs, AOs were more likely to report financial problems and at-risk/problem gambling themselves. Sociodemographic characteristics, AOs’ own gambling, and financial problems could explain the relationships between being an AO and low mental wellbeing, poor general health, and engaging in health risk behaviours.