The purpose of our investigation is to analyse the contribution of the insurance industry to sustainable finance in Spain and how this, in turn, is transforming the insurance industry itself. From there, we will also explore how insurers themselves and the concept of sustainable finance have an impact on Sustainable Development Goals (SDG) and how they may help to accomplish them. The proposed research methodology includes a section based on studies conducted by the sector’s employers’ association in Spain and another based on a series of interviews with experts and reference specialists. This is combined with an evaluation of best practices from leading entities, as well as a bibliographical review from institutional sources and monographs. Using these methods, we have demonstrated that insurance companies add value to sustainable finance from a triple perspective: as investors with high resource mobilisation potential; as expert risk managers, which now include environmental, social, and governance risks (ESG); and through the insurance business itself, through subscription policies and product and services creation/modification. Moving forward, we identified several areas of work which will be critical in defining the full potential of the insurance sector in the development of sustainable finance, such as EU regulatory development, integration of ESG risks into internal models, access to sustainable investment offer, and stakeholder valuation.