Multinational enterprises (MNEs) have been reporting on environmental and social issues beyond sole financial information for quite a while. The introduction of the United Nations’ Sustainable Development Goals (SDGs) has added a specific agenda to sustainable development globally. Although intended to be applied by states, private corporations are called upon by society to contribute to the delivery of the 17 SDGs that sit within the framework by 2030. In particular, different stakeholders, including non-governmental organisations (NGOs), governments and the press, are directly or indirectly contributing to pressure, causing companies to address how their corporations contribute to the SDGs. This chapter analyses the FT100 companies to identify how they justify their contribution to the SDGs. Drawing on legitimacy theory, the current chapter sheds light on how MNEs report on their contribution to the SDGs to manage their legitimacy and proposes a framework to detect and critically analyse whether such reporting is merely symbolic or rather substantive. The chapter discusses four legitimising strategies, conciliatory, stimulation, transparency and transformation, and draws on corporate examples regarding how they practise these strategies.