Sandra Diane Knapp FLS is an American born botanist. She is currently the president of the Linnean Society of London and is a merit researcher of the Plants Division of the Natural History Museum, London. While working at the Natural History Museum, London she has overseen the Flora Mesoamericana inventory of Central American plants. She has published several books on botanical subjects as well as a significant number of scientific articles. In 2016 she was awarded the Linnean Medal.