Explorer John Oxley camped on the present town site during his investigation of the Macquarie River in 1818.

Another theory is that it represents the adoption of a contemporary English term, "warren", meaning a game park - perhaps a reference to the picturesque riverside setting where the station hut was built (on what is now Macquarie Park) and to the large numbers of wildlife in the area.

A post office opened in 1861, a bootmaker's shop (made of bark) in 1863, a store in 1866, a school in 1867, an Anglican church in 1873, the first courthouse in 1874 and the first bridge in 1875.

The town benefited greatly with the arrival of the railway in 1898, making it the rail head for an enormous area.

The eternal water shortage was greatly eased when Burrendong Dam was opened in 1967, allowing the development of cotton and produce.