Ölper Wehr, Watermill in Ölper, Brunswick, Germany.

Ölper Wehr is the site of the former Ölper Mühle at the northeastern edge of Ölper, where the Oker's old course is spanned by a historic wooden weir with stone bank reinforcements. The river was moved about 20 metres east when the weir was rebuilt, and a concrete footbridge with metal handrails now crosses the water beside a wall carrying a long blue pipe. The mill itself is gone; the millrace and weir structures are protected monuments.

The mill passed into the ownership of the city of Braunschweig in 1388, when it was recorded as "mole in elbere". Its two grain mills, the Vordere Mühle on the west bank with six grinding courses and the Hintere Mühle on the east bank with five, together formed the most powerful of the city's mills and were called the "fürnembste Mühle" in 1579. The western branch that fed up to three further mills was filled in completely in 1891; the weir was extensively renovated in 2008.

The name Ölper Mühle survives in the street names Ölpermühle and Am Mühlengraben, while the mill itself is gone. The site is remembered through the weir and the millrace, both protected monuments, and through a residential building near the Ölper Wehr that carries Brunswick's city coat of arms with the mill and the year 1552.

The mill site lies at the northeastern edge of Ölper's old village core, at the Ölper Wehr on the Oker. The old river course, its stone bank walls and the wooden weir are still there, and the weir was extensively restored in 2008. The Mühlengraben and weir structures are protected monuments, so stay on the paths.

The mill's site is marked by a multi-storey building from the 1920s, erected where the fulling mill once stood; set into it is Brunswick's city coat of arms with the year 1552. The old course of the Oker, its stone bank reinforcements and the wooden weir structure survive beside the relocated channel.