AbstractWhile much research has explored the determinants of car ownership, there is little understanding of these factors in the context of apartment households, where off-street car parking provision is frequently stipulated by planning requirements and zero-car households are more evident. Drawing on a survey of apartment residents (n = 1316) in three Australian cities, this study aimed to understand the determinants of zero-car and car-owning apartment households. The data was analysed using binary and multinominal logistic regression, including random parameter modelling. A joint model of car ownership and off-street car parking supply was also developed to account for potential endogeneity between these two variables. The results highlight the significant association between car ownership and off-street car parking supply, alongside a range of socio-demographics, attitudes, perceptions, built environment and transport characteristics. An additional off-street car parking space, on average, was found to increase the odds of having 2+ cars, compared with zero cars, by around 10 times. The findings imply that reducing off-street residential car parking requirements can play a significant role in supporting lower car ownership levels among apartment households.