Educated at Hobart High School, he was articled to three separate firms before being admitted as a solicitor in 1884 and immediately received an offer from Brisbane solicitor, Thomas Macdonald-Paterson to join him as a partner in the firm Macdonald-Patterson, Fitzgerald & Hawthorn.

[2] At the 1902 Queensland elections, Hawthorn, representing the Ministerialists, contested the seat of Enoggera, soundly defeating the sitting Labour member, Matthew Reid.

[1] On 29 October 1908, Hawthorn was appointed Treasurer of Queensland, remaining in the role until his resignation from the Legislative Assembly on 7 February 1911.

[1] Four days after his resignation, Hawthorn was appointed to the Legislative Council,[4] but resigned on 23 March 1912 to unsuccessfully contest the seat of Ithaca at the 1912 Queensland state election where he was defeated by the Labor candidate, John Gilday.

[6] Hawthorn married Mary Stewart (died 1949)[7] at Glen Lyon[8] on 12 December 1894 and together had two daughters, Alice and Dorothy.