Bartholomew Roberts (17 May 1682 – 10 February 1722), born John Roberts, was a Welsh pirate who raided ships off America and West Africa between 1719 and 1722. He was the most successful pirate of the Golden Age of Piracy, capturing far more ships than some of the best-known pirates of this era such as Blackbeard or Captain Kidd. He is estimated to have captured over 470 vessels. He is also known as Black Bart (Welsh: Barti Ddu), but this name was never used in his lifetime.
Bartholomew Roberts is one of four pirate captains mentioned in Robert Louis Stevenson's Treasure Island.
Roberts' flag was one of several taken from real-life accounts and used in the film Pirates of the Caribbean: At World's End.