William "Willy" Brennan (also known as John) was an Irish Highwayman caught and hanged in Cork in either 1804 or perhaps 1809 or 1812, whose story was immortalised in the ballad "Brennan on the Moor". According to The Reminiscences of a Light Dragoon published in 1840, Brennan was hanged at Caher as witnessed by the author. Whilst no date is mentioned for the hanging, the author arrived in Ireland in 1808 or shortly afterwards, making an 1809 or later date for Brennan's demise more realistic. The reminiscences describe some of Brennan's exploits, his character, his partner-in-crime and ultimately his capture, trial and hanging.