Workforce diversity is a key objective of public personnel policies worldwide. We augment this discourse by exploring the complementary and multifaceted concept of workforce homogeneity. This systematic literature review clarifies an elusive concept and reveals dominant causes and consequences of public sector workforce homogeneity, synthesizing how self-selection, personnel policies, and socialization create often implicit yet persistent practices that lead to workforce homogeneity. By linking these causes with their (un-)intended consequences, this study on workforce homogeneity sheds light on an important theoretical concept for public management and identifies broad avenues for future research.