The district was inhabited by the
Wiradjuri tribe before white settlement. The first
European to visit the area was surveyor John Evans who came as close as 10 kilometres from Mendooran in 1815. Two years later it was
John Oxley's group that passed through the area while conducting one of the first inland expeditions. It is believed that the name derived from that of a local
Aboriginal tribal leader named either "Mundo" or "Mundoo".
Lucerne, wheat and sheep were established on the station in later years. The small village grew in the 1860s on the old station near the bridge which passed over the Castlereagh River. As at 1866 there were 24 residents recorded in the area. The village was called Mundooran until the arrival of the railway around 1915 when the name was changed to Mendooran. The John Bull Inn was erected to serve the passing traffic of the 1860s. A bridge was erected over the Castlereagh River in 1869 which increased the road traffic and contributed to local development. The town was laid out in 1881 with a school, police station and courthouse being built. The
Robertson Land Act of 1893 broke up the larger squatting runs and closer settlement then came about. In February 2019 Mendooran was experiencing severe shortages of water and had been placed on level six
water restrictions, the highest level of restrictions mandated in NSW. Mendooran formerly had a rugby league team, the Mendooran Tigers, who competed in the
Group 14 Rugby League competition. The town is mentioned in Banjo Paterson's poem 'The Travelling Post Office' (1894): The roving breezes come and go, the reed beds sweep and sway, The sleepy river murmurs low, and loiters on its way, It is the land of lots o' time along the Castlereagh. The old man's son had left the farm, he found it dull and slow, He drifted to the great north-west where all the rovers go. "He's gone so long," the old man said, "he's dropped right out of mind, But if you'd write a line to him I'd take it very kind He's shearing here and fencing there, a kind of waif and stray, He's droving now with Conroy's sheep along the Castlereagh. The sheep are travelling for the grass, and travelling very slow: They may be at Mundooran now, or past the Overflow. Today Mendooran (the spelling has changed since Paterson wrote the poem) is small and sleepy. It is a convenient stopover for people heading towards the Warrumbungles. ==Outdoor recreation==