Theodore A. Tinsley (October 27, 1894 – March 3, 1979) was an American writer who primarily wrote mystery stories. Tinsley wrote 27 stories featuring The Shadow for The Shadow Magazine pulp magazine. He also created Carrie Cashin, one of the first female detectives in pulp fiction, who appeared in Street & Smith's Crimebuster pulp magazine. An early series he wrote is the "Amusement Inc./Scarlet Ace" series that ran over 4 different pulp magazines in the 1930s.