John Sedgwick Cowper (1867 – July 10, 1947) was an English-born journalist, newspaper editor, woodworker and political figure in British Columbia. He represented Vancouver City from 1916 to 1920 in the Legislative Assembly of British Columbia as a Liberal.
He was born in Liverpool, the son of a naval officer, and was educated there. Cowper married in 1898 and came to Canada in 1901. From 1905 to 1910, Cowper worked for the Toronto Globe. In 1911, he moved to Prince Rupert, British Columbia and became editor of the Prince Rupert Daily News. In 1916, he moved to Vancouver. In 1924, he began working for the Saturday Tribune there. Cowper also served as editor of The Vancouver Daily World and worked on newspapers in Regina and Edmonton. He died at his home on Read Island.