John Mather (1848 – 18 February 1916) was a Scottish-born, Australian plein-air painter and etcher.
Mather was born in Hamilton, South Lanarkshire, Scotland, son of John Mather, a surveyor, and his wife Margaret, née Allan. Mather worked as a house decorator. Mather studied art at the Royal Glasgow Institute of the Fine Arts and migrated to Australia in 1878.
In 1880, Mather was partly responsible for the decoration of the dome of the Royal Exhibition Building, Melbourne. He was appointed to the board of trustees of the Public Library, Museums and National Gallery of Victoria in 1892. and was a founding member of the Victorian Artists' Society, president in 1893–1900, 1906–08 and 1911. Mather was a member of the Felton Bequest Committee from 1905–16 and as trustee, strongly supported Australian art.
As a painter, Mather was also involved in the bohemian Artists' Camps of Sydney. In 1912 along with Frederick McCubbin, Max Meldrum, Walter Withers Mather formed the breakaway Australian Art Association.
Three of Mather's own paintings, Autumn in the Fitzroy Gardens in oils, and Morning, Lake Omeo and Wintry Weather, Yarra Glen, both watercolours, were purchased by the National Gallery of Victoria.
Mather died of diabetes at his home, Cadzow, South Yarra, Victoria on 18 February 1916; he was buried in the Cheltenham Pioneer Cemetery.