Horrocks Highway is a major north–south arterial route through regional South Australia, between Quorn in the Flinders Ranges, and Gawler, on the north-eastern fringe of suburban Adelaide.

[3] Horrocks Highway commences at the intersection with Flinders Ranges Way in Quorn and heads in a southerly direction as a single carriageway, two-lane road, through the grain fields around the regional towns of Wilmingon at the eastern side of Horrocks Pass, continuing south to cross the Broughton River near Yacka.

It crosses the Light River and the environment changes again, grain storage bunkers and silos to urban build-up, before eventually terminating at the interchange with Sturt Highway, and continues south into central Gawler and into suburban Adelaide as the remaining alignment of Main North Road.

The highway follows the route established in the early years of the colony by explorer John Horrocks and was a major route for farmers and graziers to reach the capital, passing through rich farmland and the Clare Valley wine region.

Horrocks Highway was previously declared as part of Main North Road, from Wilmington to Gawler Belt; this section was renamed in 2011 to honour John Horrocks, an early explorer and pioneer in the region.