In July 1824, Edward O'Shaughnessy was convicted of collecting taxes under false pretences in Dublin, and sentenced to seven years transportation to New South Wales. On arrival in the colony, O'Shaughnessy was assigned as a convict servant to Robert Howe, the government printer and proprietor of the Sydney Gazette. O'Shaughnessy lived at the office of the Gazette until his sentence expired in 1831.
Evidently a man of some education, O'Shaughnessy proved useful to the Howes as a journalist, subeditor, and a literary contributor. His reviews of the performances at Barnett Levey's Theatre Royal were among the earliest dramatic criticism published in Australia. He also contributed about 30 signed poems to the Gazette. According to the ADB, most of these were 'melancholy lyrics in the style of Thomas Moore', though later he produced 'satire in the manner of Byron'. When he became editor of the Gazette, O'Shaughnessy would also import stories and poetry from Blackwood's Magazine into the paper.
In November 1832, Ann Howe made O'Shaughnessy editor of the Sydney Gazette, and he soon found himself embroiled in the often savage world of early colonial politics. The Gazette supported the liberal government of Richard Bourke in the dispute with prominent magistrates and settlers over the issues of convict discipline and the rights of emancipists, and O'Shaughnessy's convict background saw the paper lampooned as 'The Prisoners' Journal'. When he defected to the Sydney Herald in the mid 1830s, however, O'Shaughnessy supported the opposite side with equal vehemence. He was working at the Herald when he died at the early age of 39.