Reinder ("Rein") Boomsma (19 June 1879, Schagen, North Holland - 27 May 1943, Neuengamme concentration camp) was a Dutch footballer, who played for Sparta and the Dutch national team.
Boomsma was born in Schagen, North Holland in 1879, and moved to Rotterdam in 1888. He started to play football on the streets, where he was noticed by Kees van Hasselt. He joined Sparta sometime around 1895. He would remain with the club until his retirement from football in 1907. A year later, in 1908, he was made honorary member of the club.
Boomsma scored the only goal for Sparta in the league game against reigning champions RAP of Amsterdam on October 29, 1899. The match was the first charity game in the Netherlands, held to support the Boer cause in the Second Boer War. The match grossed 1,201 guilders and 51.5 cents.
Boomsma was also part of the first Dutch national football team, that played against Belgium on April 30, 1905. He also played for the Netherlands in the return match in Rotterdam on May 14, 1905. These would remain the only matches Boomsma played for the Netherlands.
Boomsma volunteered to join the Royal Netherlands Army on July 1, 1898, and eventually became a colonel. Boomsma was stationed in Assen when Nazi Germany invaded the Netherlands in May 1940; Boomsma's unit was moved to Rotterdam to defend the city. After the Dutch surrender, Boomsma retired from the army and joined the Dutch resistance. He was betrayed, and died in the Neuengamme concentration camp.