Walter Bruno Gratzer (20 September 1932 – 20 October 2021) was a German-born British biophysical chemist. He was professor of biophysical chemistry at King's College London and an author and reviewer of popular science. He was the first Nature news correspondent appointed by editor John Maddox. Oliver Sacks of Nature writes that his reviews have high literary quality and show knowledge of a wide range of topics. He was a friend of James D. Watson, and wrote the introduction and afterword of his A Passion for DNA.