[2] The municipality (Gemeinde) of Oppenweiler is located in the Rems-Murr district of Baden-Württemberg, one of the 16 States of the Federal Republic of Germany.

Oppenweiler is situated between the Löwenstein Hills to the north and the Backnanger Bucht [de] to the south, in the greater region of the Swabian-Franconian Forest.

Also in the municipal area is the industrial district of Wachthäusle and the abandoned villages of Charlottenhof and Giselmar.

The blazon is identical to that of Baden's, but with the addition of the ax heads to reference the House of Sturmfeder [de], who inhabited Oppenweiler from 1288 until their extinction in 1901.

This coat of arms was awarded to Oppenweiler with a municipal flag by the government of Baden-Württemberg on 14 November 1955.