Joseph Tice Gellibrand (1792 – 1837) was the first Attorney-General of the British colony of Van Diemen's Land (now the Australian island province of Tasmania), where he gained notoriety with his attempts to establish full rights of trial by jury.

Gellibrand was also later part of an ill-fated expedition into the region west of Geelong, where he disappeared and was assumed to have been killed by Aboriginal people in the Otway Range.

Gellibrand studied law, was called to the bar and on 1 August 1823 was appointed Attorney-General of Van Diemen's Land (now Tasmania) with a salary of £700 a year and the right "to practise as a barrister under the same restrictions as are observed in this country".

At the opening of the Supreme Court gave an address as leader of the bar, in which he spoke of trial by jury "as one of the greatest boons conferred by the legislature upon this colony".

The full benefit of trial by jury had, however, been withheld from the colony, and Gellibrand's speech is held by some to have been the opening of a campaign for an unconditional system.

Gellibrand was a believer in the liberty of the subject, and he was consequently bound to fall foul of a man with the autocratic tendencies of Governor George Arthur.

[1] At the beginning of 1825 Robert William Lathrop Murray, editor of the Hobart Town Gazette, began criticising the colonial government in his paper.

[1] As early as January 1827, Gellibrand, in partnership with John Batman applied for a grant of land in the as-yet un-colonised region at Port Phillip.

Gellibrand, having a strong foundation in law, drew up this Batman Treaty which stipulated that the Aboriginal people would hand over all of the land within ten miles of the northern shore in exchange for a yearly hand-out of basic provisions.

[6] On 4 February, Gellibrand travelled to the Geelong region, guided by William Buckley, an ex-convict who had lived with the local Wathaurong people for over thirty years.

When Gellibrand and Hesse failed to arrive at Melbourne, a search party consisting of five prominent Geelong pastoralists, including Frederick Armytage and Thomas Roadknight, was immediately organised.

[7] The search party's report that they had solved the mystery and exacted justice was strongly discredited, as no bodies nor any personal artefacts of Gellibrand or Hesse were recovered.

It was argued that the Barrabool men had only led the search party to Lake Colac so as to take violence upon a tribe they had animosity with and to obtain the reward offered.

[9] In July, Alexander McGeary led another search party after information was given that two white men were living with an Aboriginal clan towards the western regions.

[10] In 1844, George Allan, a pioneer pastoralist of the Warrnambool region, learnt that Gadubanud people from the Otway Range had seven years previously encountered two white men fitting the description of Gellibrand and Hesse.