Matt Ritter (born 7 September 1974, in California) is an author, editor and botany professor at California Polytechnic State University at San Luis Obispo.
He specializes in cultivated trees, and is an expert of the genus Eucalyptus.
Ritter was Editor-in-Chief of Madroño, the journal of the California Botanical Society for five years .
He is the California coordinator of the Official National Register of Big Trees.
Ritter is a contributing author to the second edition of the Jepson Manual of California native plants, and to the Flora of North America projects.