Carst Jan Posthuma (11 January 1868 – 21 December 1939) was a Dutch cricket player of the late 19th/early 20th century.

Posthuma played 72 times for the Dutch national team up to 1928, when he was sixty years old.

He was also the first Dutchman to take 100 wickets in a season in 1900, and the first to score a century in domestic cricket in 1894.

[2] Posthuma spent the 1903 season in England playing amateur cricket.

Dogged by injury, he missed several weeks and was never able to bowl at his quickest, but he played five first-class games for W. G. Grace's London County Cricket Club.