Since 1952 a mining town in its own right within Wolfenbüttel district, it was incorporated into the Goslar municipality on 1 July 1972.

On 1 April 1819 an agency of the Brunswick Postal Service was opened on the old mail route from Wolfenbüttel to Harzburg (Neustadt).

[1] Today Oker is home to chemical-metallurgical, recycling and specialised industrial concerns, like Harz-Metall and Norzinco.

The largest employer in Oker and the district of Goslar is a factory belonging to H.C. Starck company, a former daughter of Bayer sold to Advent International and The Carlyle Group in 2007.

The largest sports club is VfL Oker, which is especially renowned for its pan-regional table tennis team.