Sir Robert George Mappin Fenwick KNZM KStJ (5 May 1951 – 11 March 2020) was a New Zealand environmentalist, businessman and professional director. Fenwick co-founded the organic composting service Living Earth Ltd, the NZ Natural bottled water brand and Te Matuku Oysters and held a number of board and advisory panel positions. His conservation and sustainability work included leadership roles in the Predator Free 2050 movement, co-founding the New Zealand Business Council for Sustainable Development and several leadership roles in Antarctica.