The Independent Senate Group (Dutch: Onafhankelijke Senaatsfractie, OSF) is a parliamentary party in the Dutch Senate with one senator, representing several provincial parties. The Dutch Senate is elected by the legislatures of the provinces. In 1995, several provincial parties and the Greens proposed their own list. Marten Bierman nominated by The Greens and second on the list was elected senator by a preference vote. In 1999, Bierman was re-elected.