Portengen is a hamlet in the Dutch province of Utrecht.

It is located in the municipality of Stichtse Vecht, 1 km (0.62 mi) northeast of Kockengen.

Portengen was a separate municipality from 1818 to 1857, when it was merged with Breukelen-Nijenrode.

[3] The hamlet was first mentioned in 1217 as Britannien, and is a reference to Brittany, France.

It started as a peat excavation colony during the 11th and 12th century.