Born in Ireland, Edward Geoghegan studied medicine after leaving school. In June 1839, however, he was convicted in a Dublin court of obtaining paper under false pretences and sentenced to seven years in the Australian colonies. He arrived in Sydney the following year, aged twenty seven, on the ship Middlesex. Because of his medical training, Geoghegan was given 'special employment' during his confinement on the Sydney Harbour penal establishment at Cockatoo Island. His duties were as a dispenser in the medical department, and, within a short time, he was granted permission to go ashore once a week. During these periods of leave, he was able to make the acquaintance of people associated with the Royal Victoria Theatre. One of these was Francis Nesbitt (McCrone), who became his patron and encouraged him to try his hand at writing works for the local actors.
Geoghegan's literary and theatrical aspirations were put briefly on hold, however, when he was caught by the authorities in a raid on the island and found to have been acting as a courier of illegal items of trade. Reduced to a common labourer, with his leave stopped, Geoghegan's medical background once again saved him, and he was eventually restored to his previous position. The incident did not help his cause regarding an early release, however, and he was made to serve his full seven-year sentence. Once allowed to regain his leave rights, Geoghegan was able to return to his theatrical activities, and between 1844 and 1845, he became the most performed of the Royal Victoria's resident playwrights, with at least eight of his works staged. These were presented either under pseudonyms or anonymously, as there existed a prohibition on convict actors (and subsequently convict playwrights) appearing on colonial stages.
The plays known to have been written by Geoghegan during this period include his two most famous works: The Hibernian Father (1844) and The Currency Lass (1844), which was one of the first professionally produced plays with a local setting. His other works include Ravenswood (1843), The Last Days of Pompeii (1844), A Christmas Carol (1844), The Royal Masquer (1845), Captain Kyd (1845), Lafitte the Pirate (1845), and The Jew of Dresden (unperformed). While there are several other works that, though they are attributed to other authors, some historians believe are Geoghegan's (based on handwriting analyses), he was also on a number of occasions accused of plagiarism. There are at least two other plays that may possibly have been written by Geoghegan, but the manuscripts have unfortunately been lost.
Edward Geoghegan was given his ticket of leave in 1846 and initially tried to make a living through work at the Royal Victoria Theatre. Despite having been the most successful Australian-based playwright of the early 1840s, his craft had unfortunately yielded him less than six pounds in all, with the doubtful bonus of 'several poetical addresses' (qtd. in Roger Covell's Australia's Music: Themes of a New Society, p.xix). Without his patron (Nesbitt had left for Victoria, where he died the following year) and with no great prospects for him in Sydney, Geoghegan travelled south in search of work. A letter he wrote from Victoria in 1852 to the Colonial Secretary requesting the text of The Jew of Dresden so that he could recopy it for a possible London production is virtually all that has been found, although his play A Trip to Geelong is known to have been produced in Melbourne in 1861. Although little is known about Geoghegan from this time on, he appears to have retired from writing for the theatre. This likely due to his having settled in Singleton, NSW, where in 1866 the became the municipality's first Town Clerk.