James C. A. Whetter (20 September 1935 – 24 February 2018) was a British historian and politician, noted as a Cornish nationalist and editor of The Cornish Banner (An Baner Kernewek). He contested elections for two Cornish independence parties. A prolific writer, Dr James Whetter was the editor of Mebyon Kernow's monthly magazine Cornish Nation in the early 1970s before later becoming active in the Cornish Nationalist Party. While active in Mebyon Kernow he authored A Celtic Tomorrow - Essays in Cornish Nationalism (MK Publications 1973) and The Celtic Background of Kernow (MK Publications 1971), the latter intended to assist schoolchildren in a better understanding of Cornish Celtic history and culture.