[1] It was proclaimed by Governor Frederick Robe in 1846 and named for the Onkaparinga River valley, which flows from north east to south west through the hundred.

The main towns within the hundred are Woodside, Lobethal, Balhannah and, on the southern fringe, Hahndorf.

The Adelaide suburb of Crafers is another major population centre in the hundred.

The earliest local government within the hundred was established with the formation of the district councils of Onkaparinga and East Torrens on the same day in 1853, which incorporated the entire hundred.

In 1858 the District Council of Crafers seceded from the south of the hundred.