Marrit Boonstra (born 25 September 1988) is a former professional tennis player from the Netherlands.

Boonstra, who was born in Groningen, played tennis as a right-hander with a two-handed backhand.

Her junior career included a win over Caroline Wozniacki, whom she also partnered to make the girls' doubles quarterfinals of the 2006 Wimbledon Championships.

[1][2] As a 17-year-old, she played three doubles rubbers for the Netherlands in the 2006 Fed Cup competition, teaming up with Dutch veteran Brenda Schultz-McCarthy to win all three matches.

[3] Boonstra received a wildcard to compete in the main draw of the 2006 Ordina Open, a WTA Tour tournament in Rosmalen.