Catherine Cate Coblentz (June 5, 1897 – May 30, 1951) was an American writer, best known for her children's books in the 1930s and 1940s.

Born in Hardwick, Vermont, Catherine Cate worked during World War I at the National Bureau of Standards in Washington, D.C., where she met her future husband, William Coblentz, an American scientist who was a pioneer in the field of infrared spectroscopy.

In honor of her later work, she was presented with a Distinguished Alumni Achievement Award by her alma mater in 1945.

In the mid-to-late 1940s, Coblentz was instrumental in raising money to buy the land on which the Cleveland Park Neighborhood Library was built on Connecticut Avenue in Washington, D.C. A set of windows, with illustrations based on her books, remain on display in the library.

Catherine Cate Coblentz, her husband, and an infant daughter are buried in Rock Creek Cemetery in Washington, D.C. (Section O).