The thesis rests on the argument that the literature on Corporate Social Responsibility (CSR) and the law has, so far, largely neglected the contribution that private law makes or could make to the promotion of CSR. The primary research question of this thesis is therefore to analyse the extent to which English private law already promotes and/or could better promote CSR. Based on the analysis of four substantive areas of private law (company law and corporate governance, contract law, consumer law and tort law), one of the overall contributions of this thesis is to demonstrate that private law plays an important role in the regulatory framework of CSR. Whilst this analysis shows that there are limitations in the promotion of CSR in English private law, it is argued that private law already makes an important contribution to the promotion of CSR. Moreover, it could make an even better contribution if some of its limitations were addressed. The analysis in the substantive chapters demonstrates the different ways in which private law promotes CSR: First, CSR is, at least in part, law. Secondly, private law provides mechanisms to incorporate and to enforce CSR commitments. Thirdly, private law contributes to hybrid regulatory approaches to CSR, i.e. systems where different forms of regulation such as private law, public law and soft law standards interact. The thesis demonstrates that the effectiveness of the regulatory system in promoting CSR can be enhanced by regulation through public and criminal law of companies in their home state, in combination with national private law. However, if private law were to make an even better contribution then some changes would be needed to the areas of private law analysed in the substantive chapters. The thesis will therefore conclude with a list of substantive recommendations for changes to English private law.