Abstract Background Social distancing is a key behavior to minimize COVID-19 infections. Identification of potentially modifiable determinants of social distancing behavior may provide essential evidence to inform social distancing behavioral interventions. Purpose The current study applied an integrated social cognition model to identify the determinants of social distancing behavior, and the processes involved, in the context of the COVID-19 pandemic. Methods In a prospective correlational survey study, samples of Australian (N = 365) and U.S. (N = 440) residents completed online self-report measures of social cognition constructs (attitude, subjective norm, moral norm, anticipated regret, and perceived behavioral control [PBC]), intention, action planning, habit, and past behavior with respect to social distancing behavior at an initial occasion. Follow-up measures of habit and social distancing behavior were taken 1 week later. Results Structural equation models indicated that subjective norm, moral norm, and PBC were consistent predictors of intention in both samples. Intention, action planning, and habit at follow-up were consistent predictors of social distancing behavior in both samples. Action planning did not have consistent effects mediating or moderating the intention–behavior relationship. Inclusion of past behavior in the model attenuated effects among constructs, although the effects of the determinants of intention and behavior remained. Conclusions Current findings highlight the importance of subjective norm, moral obligation, and PBC as determinants of social distancing intention and intention and habit as behavioral determinants. Future research on long-range predictors of social distancing behavior and reciprocal effects in the integrated model is warranted.