The existing literature on the impact of ownership structure on corporate social responsibility (CSR) showed inconsistent results and disregarded the possibility of non‐linear patterns in the relationship. The present study examines the non‐linear relationship between ownership structure (family, foreign, institutional, and government) and CSR expenditure of listed non‐financial service sector firms in India. Further, the moderating effect of board variables, including board size, board independence, multiple directorships and gender diversity, is explored in the ownership structure‐CSR nexus. Based on a balanced panel dataset of 243 non‐financial service sector companies listed in India, the study observed an inverse U‐relationship between institutional ownership and CSR. The study also found that family, foreign, and government ownership positively influence the firm's social engagement. However, the study could find partial support for the moderating role of the four board characteristics; board size, board independence, multiple directorships and gender diversity in ownership‐CSR association. The study contributes to existing CSR and corporate governance literature by exploring one of the major factors (ownership structure) impacting CSR and the role of board variables in the association.