It is the most northern of the eleven hundreds of the County of Adelaide and was named in 1846 by Governor Frederick Robe after the Barossa Range.

The principal towns within the hundred are Williamstown, Lyndoch, and Gawler East at the western edge.

Other localities include Kalbeeba, Concordia, Rosedale, Sandy Creek, Cockatoo Valley, Barossa Goldfields, Pewsey Vale, Altona and Rowland Flat.

Dual local government was established for the hundred in January 1854 with the formation of the District Council of Barossa West.

After lobbying by dissatisfied residents of Gawler at the confluence of the North Para and South Para rivers, the Town of Gawler was established in 1857 to govern the township of Gawler, annexing a small portion of Barossa West.