Percival Stanley Brookfield (7 August 1875 – 22 March 1921) was an Australian politician and militant trade unionist.

After spending about 6 years at sea working on various merchant ships, at his request he was discharged from his service on the vessel "Godiva", with an endorsement of good conduct, in Port Melbourne in 1894.

He became an official of the Amalgamated Miners' Association and led the Broken Hill campaign against the introduction of conscription.

The by-election had been caused by the resignation of the previous member John Cann who had accepted the position of Railways Commissioner.

[2] Brookfield won the seat with 54% of the primary vote and increased this to 57% at the general election that was held one month later.

[3] In parliament he became a leading left-wing advocate and expressed sympathy for the Industrial Workers of the World and the Bolshevik Revolution.

At the March 1920 state elections Brookfield contested the seat of Sturt for the Socialist Labor Party after its amalgamation with the Industrial Socialist Labor Party, and, under the multi-member proportional representation system then used, he was the first candidate elected with 27% of the primary vote.

He supported the Labor government of John Storey and used his position to improve industrial conditions for Broken Hill miners and to overturn the convictions of Australian IWW members gaoled in 1916.

[5] Brookfield died as a result of wounds received when trying to disarm a deranged Russian emigre, Koorman Tomayoff, at the Riverton railway station in South Australia on 22 March 1921.

On the same train that had stopped at Riverton S.A. was Constable Edmund A. Kinsela of the New South Wales Police Force.

[6] The South Australian Governor, Sir Archibald Weigall met with Constable Kinsela the following day and warmly congratulated him on his heroism.

The Russian was directing his attention to Mr Brookfield, who was holding my revolver in front of him, and I was on the outside, thinking to come up at the side of him.