Boonstra is a Dutch surname. Notable people with the surname include:
Albert Boonstra (born 1957), Dutch swimmer
Clarence A. Boonstra (1914–2006), American ambassador
Cor Boonstra (born 1938), Dutch chief executive
Dirk Boonstra (1893–1944), Dutch police officer
Dirk Boonstra (1920–1944), Dutch Resistance member
Lieuwe Dirk Boonstra (1905–1975), South African paleontologist
Tjabel Boonstra (1899–1968), Dutch cyclist