Corporate social responsibility (CSR) is the way that organizations embed social, environmental, and economic concerns into what they do. Gambling operators use CSR to get positive publicity and defend their existence. This systematic review examined the current state of knowledge on the socially responsible behaviour of gambling operators. A total of 53 articles were included. Articles had to be published in English in a peer-reviewed journal. More than half (53%) of the articles used quantitative methods. Most articles focused on the issue of CSR from the point of view of gambling companies (58%). The authors identified four main research topics: (1) effects of CSR; (2) CSR reporting; (3) CSR implementation; and (4) responsible gambling. The focus of the articles shifted between 2001 and 2019. Between 2001 and 2015, articles mostly focused on the effects of CSR. Between 2019 and 2021, CSR reporting and responsible gambling started to become important topics.