Billy Thompson, sometimes known as Texas Billy Thompson (1845 – September 6, 1897) was an Old West gunman and gambler, and the younger brother of the famous gunman and lawman Ben Thompson. The younger Thompson brother never achieved the fame that his brother achieved, and in his own lifetime was mainly referred to as the unpredictable and troubled younger brother of Ben Thompson. Factually, however, while a dangerous man, he also was a formidable opponent in a gunfight.