William Brocius (c. 1845 – March 24, 1882), better known as Curly Bill Brocius, was a gunman, rustler  and an outlaw Cowboy in the Cochise County area of the Arizona Territory during the early 1880s. His name is almost certainly an alias, and there is evidence linking him to another outlaw named William "Curly Bill" Bresnaham who had committed an 1878 attempted robbery in El Paso, Texas.