This paper examines the employment representation of non‐English‐speaking background (NESB) immigrants in the Australian public sector. It explores the extent to which the (federal) Australian Public Service (APS) legislation for managing diversity and equity has influenced employment outcomes of NESB employees in the APS. Drawing from APS Commission reports and APS Statistical Bulletins from 2001 to 2015, our findings indicate that the general representation of APS employees from NESB (first‐ and second‐generation immigrants) is trending slowly upward. However, first‐generation NESB immigrants’ representation had only increased from 3.1% in 2001 to 5.1% in the decade to 2011. These proportions are well below the broader workforce representation of first‐generation NESB employees of 16%. The NESB group also remains significantly under‐represented at the executive level, indicating limited impact by the Australian Public Service Act (PSA) on the employment outcomes of employees from NESB. Such findings raise serious questions around low levels of cultural diversity in the APS. Our study indicates that progress towards increasing such diversity remains slow and problematic. We draw on institutional theory to help explain why this may be the case, and suggest future directions for research and policy.