ABSTRACT A central finding of scholarship on employee ownership (EO) is that EO has the strongest impacts on employee outcomes when implemented with other management practices that are typically associated with high-performance work systems (HPWS). However, our explanations for why these complementary practices matter remain underdeveloped. In this paper, we examine whether the extent to which employees feel like owners, using the construct of psychological ownership (PO), mediates the impact of three HPWS practices on four employee outcomes in a dataset of 881 employees in nine companies with employee stock ownership plans (ESOPs) in the United States. Our findings support our core argument that these practices make it more likely that employees will feel like owners, which in turn leads to positive impacts on employee outcomes. More specifically, we find that the extent to which employees perceive that they have influence, are engaged as owners through information sharing and business literacy training, and receive high quality communications about EO are positively associated with PO, and that PO is positively associated with organizational commitment, turnover intention, voice behavior, and helping behavior. We discuss the theoretical, management, and policy implications of our analysis and findings.