Henry Augustus Ellis (24 July 1861 – 3 October 1939) was an Irish Australian physician and federalist, important in the promotion of federation in Western Australia.
Western Australia did not take part in the referendum held in 1898, and the government under Forrest was opposed to the proposals for federation as late as the end of 1899.
Some 28,000 signatures were obtained to this petition and an immense amount of propaganda matter, mostly drafted by Ellis, was sent to the British press and members of the House of Commons.
As a result, Chamberlain intimated to Forrest that if the electors of Western Australia were not given an opportunity of voting on the question of federation, the Imperial parliament would be compelled to consider seriously the request of the people of the goldfields.
In 1904 Ellis was elected to the Western Australian parliament but only served until 1905, when he left the Labor Party to run unsuccessfully as an independent.