In this article, David Rouch considers growing attention among investors to the question of whether they are legally required or permitted to take steps to tackle humanity’s core sustainability challenges. He outlines some of the circumstances in which they may, potential challenges in doing so and how they can be approached. The article is based on analysis undertaken across 11 jurisdictions, including the major investment hubs, which resulted in a report on the subject for the UNEP Finance Initiative, PRI and The Generation Foundation, published by Freshfields Bruckhaus Deringer in 2021: A Legal Framework For Impact: Sustainability Impact In Investor Decision-making.