Maartensdijk was a separate municipality until 2001, when it merged with De Bilt.
Until 1812, Maartensdijk was called Oostveen, meaning "east fen". The conversion of fen or wetland area into agricultural land was initiated by Bishop Godebald of Utrecht (1114–1127) when the Kromme Rijn ("Crooked Rhine") was dammed in 1122 at Wijk bij Duurstede. The same Bishop Godebald gave land development contracts to those who would completely drain this land and make it arable; Oostveen was a large section of this area.
The oldest settlement in the area is the village of Voordorp, which gradually became known as Blauwkapel because the chapel's interior was entirely blue. The name Voordorp has been revived and applied to a new northern district of the city of Utrecht. Blauwkapel still exists and is part of the Waterline and Fort defense system established to protect the provinces of Holland from inland invaders by flooding the land strategically and building fortresses where flooding was not feasible. Such a fort, the largest in this defense system, surrounds the old chapel. As land reclamation of Oostveen moved northward, a new settlement arose on the Oostveen lands that was dedicated by the Dean of St. Martin's Cathedral, Utrecht in protectione et iustitia Sancti Martini. This settlement was the seat of the gerecht or canton of Oostveen, and in 1812 was renamed Maartensdijk.
