In the 1865 electoral redistribution, the House of Representatives focussed its review of electorates to South Island electorates only, as the Otago Gold Rush had caused significant population growth, and a redistribution of the existing population. Fifteen additional South Island electorates were created, including Ashley, and the number of Members of Parliament was increased by 13 to 70.
The Ashley electorate was formed from a corner of Cheviot electorate, and included the towns of Ashley, Amberley, and Oxford. The electorate's boundaries remained roughly the same until the 1881 election, when it expanded slightly into Kaiapoi electorate and Amberley was returned to Cheviot. In the 1887 election, the electorate expanded westwards into Cheviot's southern tip. In the 1890 election, Cheviot itself was abolished, and the majority of its territory was absorbed into Ashley — to compensate, territory was taken from Ashley in the south and given to Kaiapoi. In the 1893 election, Ashley expanded further north, taking the town of Kaikoura from Wairau electorate, but ceded Oxford to Kaiapoi in the south. In the 1902 election, Ashley was dissolved, being replaced with an electorate called Hurunui, covering much the same area.