Jowett was born in Yorkshire, England, at Bradford, on 6 January 1858 to Joseph Jowett and Sarah, née Craven. He migrated to Melbourne in Australia in 1876 with his father and elder brother Charles, where he worked on The Argus and contributed to the Australasian Banking Record.
He attended Mr James Ward"s Classical School at Clapham Common in London and went to his uncle"s wool mill at Thornton.
Jowett gradually accumulated property in Queensland, New South Wales and Victoria, eventually controlling more than forty properties including Palparara, Boorara and Kynuna Stations and owned over six million acres (24,000 km²). The Bulletin stated at his death that he had owned more sheep than anyone in the world. He was appointed growers" representative on the Central Wool Committee (a wartime institution) in 1916, and also served on the Commonwealth Bureau of Commerce and Industry and the Victorian Meat Advisory Committee.
Jowett was influenced as a young man by Sir Frederick Sargood.
His early political activity consists of membership of the Young Victorian Patriotic League and campaigning for conscription. In 1917 he became the first Victorian vice-president of the Nationalist Party.
In the election of that year he unsuccessfully contested the seat of Maribyrnong. His seat was abolished in 1922, and he contested Bendigo instead, but was unsuccessful.
He continued to be active in the Country Party.
An advocate of electoral reform and proportional representation, Jowett always encouraged the immigration of Britons to Australia. He also produced a number of publications, and was a company director for some years. On 14 April 1936 he died at Strathane, one of his properties in the Queensland district of Leyburn, and was buried at Street Kilda.
