Guthlac Ceri Klaus Peach (26 October 1939 - 3 October 2018) was a geographer from Bridgend, Wales. He was an undergraduate (BA 1961), graduate student (DPhil, 1964), and lecturer at Merton College, Oxford before being appointed to a lectureship in geography at St Catherine's College, Oxford (known colloquially as St Catz) in 1965 at the age of 26. He held this post jointly with a lectureship at Keble College, Oxford and a Faculty Lectureship at the University of Oxford.