Explorers John Oxley, Charles Sturt and Thomas Mitchell passed through the area at various times before pastoralists moved in and the town was gazetted in 1859. The late 19th century saw a boom in the wool industry and Walgett served as a port for paddle-steamers working the Murray-Darling river system.
A post office was gazetted for "Wallgett on the Barwin River" in 1851 and the town sites were surveyed in 1859. The district would have been occupied prior to this by squatters and their livestock.
The town of Walgett was proclaimed on 20 March 1885. The surveyor, Arthur Dewhurst, mapped the town, naming the three main streets after the British Prime Ministers: Pitt, Fox and Peel. Arthur Street was named after another surveyor. Walgett Courthouse was built in 1865.
It was once a port for paddle steamers in the late 1800s that plied the Murray-Darling river systems. The first steamer reached Walgett in 1861 and travelled to the town regularly until c.1870.
Euroka Station was purchased by Fred Wolseley in 1876 and was the site of the invention of the Wolseley Shearing Machine. The machine was tested at Bourke in 1888 on 184,000 sheep to eventually revolutionise the shearing industry. Walgett's recent history includes the Freedom Rides in the late 1960s. The Freedom Riders arrived in Walgett on February 15th 1965. They protested outside the Walgett RSL Club because they had been told the club was refusing to admit Indigenous ex-servicemen. After their protest their bus was run off the road by a car driven by an unidentified person. This event led to Walgett, the Freedom Riders and the plight of Indigenous Australians in rural New South Wales getting national and international media attentions.