Objectives: The COVID-19 pandemic reduced access to gambling and contributed to widespread psychological distress. Psychological distress is a known risk factor for problem gambling as it can motivate excessive gambling as a coping response. The availability of gambling is considered a factor in maintaining problems. This paper aimed to investigate the impact of the shutdown of gambling venues on Australians, particularly among those vulnerable to mental health problems and gambling disorder. Methods: Australian adults who had gambled at least once in the past 12 months ( N = 764, 85.2% male) completed an online cross-sectional survey. Self-report measures retrospectively assessed typical monthly gambling frequency and expenditure before and after the COVID-19 venue shutdown, problem gambling, and psychological distress. Results: Significant median decreases in gambling frequency were observed, both online and overall. No relationship was found between psychological distress and baseline or increases in gambling. Greater problem gambling severity was related to higher baseline gambling, but not to increases in gambling. Exploratory analysis showed that individuals engaged in moderate-risk gambling, but not problem gambling, were more likely to report increased gambling frequency compared to nonproblem and low-risk gamblers combined. Conclusions: Findings provide important insights into how changes in availability influence gambling participation, and for understanding the effectiveness of forced restrictions and venue exclusion strategies. Most people moderated their gambling when venue-based gambling was unavailable and opportunities for sports betting were limited. However, harms experienced by individuals with some gambling problems may have been exacerbated during the period of limited access. Policies to enhance prevention and treatment of gambling problems are necessary even when availability is reduced.