Joseph Hobson Jagger (2 September 1830 – 25 April 1892) was an English textile industry businessman from Yorkshire, who in around 1881 is said to have "broken the bank at Monte Carlo" by identifying and exploiting biases in the wheels of the roulette tables there.

Around 1880/81 he and his eldest son Alfred, with his nephew Oates Jagger, travelled to Monte Carlo with money borrowed from friends and family.

[2][4] After studying the tables at the Casino de Monte-Carlo for a month to determine which numbers came up most frequently he began to place successful bets.

In a ceremony devised by François Blanc, the original owner of the casino, a black cloth was laid over the table in question, and the successful player was said to have broken the bank.

[9] He is the subject of a biography by his great-great niece Anne Fletcher titled From the Mill to Monte Carlo: The Working-Class Englishman Who Beat the Monaco Casino and Changed Gambling Forever, published by Amberley in 2018.