Over the past two decades, many problematic/excessive behaviours have increasingly been conceptualized as addictions due to their similarity with more traditional psychoactive substance addictions. The primary aim of the present study was to simultaneously examine the factor structure of three psychoactive substance addictions (alcohol use, cigarette smoking, and substance use) and seven behavioural addictions (sex, social media use, shopping, exercise, online gambling, internet gaming, and internet use), using exploratory factor analysis (EFA; N = 481) and confirmatory factor analysis (CFA; N = 487). A total of 968 participants completed an online survey including ten psychometric scales assessing the ten different potentially addictive behaviours. EFA supported a two-factor solution, with different factors for the psychoactive substance and behavioural addictions (excluding exercise addiction). CFA supported the two-factor model in a separate sample. There was good support for the concurrent and discriminant validities of the CFA latent factors and the reliability of the behavioural latent factor in the two-factor CFA model. While there was support for the concurrent and discriminant validities of the psychoactive substance latent factor, there was insufficient support for its reliability. The taxonomic, theoretical, and clinical implications of the findings are discussed.