George Roberts was appointed to the position of Assistant Surgeon on 24 May 1810.
He was appointed Assistant Surgeon to the Redwing in 1818.
He was promoted to the position of Surgeon in 5 November 1823 
George Roberts was employed as Surgeon Superintendent on four convict ship voyages to Australia:
Lord Melville departed the Downs 6th June 1830 and arrived at Port Jackson 21st October 1830.
Gilmore departed London 27 November 1831 and arrived in Van Diemen's Land 22 March 1832.
Heroine departed Portsmouth 15 May 1833 and arrived at Port Jackson 19th September 1833.
Waterloo departed Portsmouth 20 November 1834 and arrived Hobart 3 March 1835
Waterloo departed Cork 21 May 1836 and arrived Port Jackson on 6 September 1836.
Emigrant Ship Surgeon Superintendent
George Roberts was employed Surgeon Superintendent on the emigrant ship William Nicol in 1837. The Sydney Herald reported in October 1837 that the William Nicol was the first vessel chartered by the Government for the conveyance of Highlanders to Port Jackson. They arrived from the Isle of Skye under the superintendence of an old visitor Dr. Roberts R.N. In the ship there were 311 persons including 73 female adults and 169 children. He was on the List of Surgeons given advances or remunerated for services as Surgeon Superintendents in 1838. He was paid £20/1/9d for his services on the William Nicol. New South Wales - 
His next appointment was to the emigrant ship Lady Nugent. Lady Nugent departed Gravesend 23rd July 1838 and arrived on 27 November 1838 in Sydney. Two hundred and thirty eight Government emigrants came under George Roberts care.
The Sydney Herald reported in February 1840 that the James Pattison arrived in Sydney with 187 Government Immigrants under the superintendence of Dr. Roberts. The James Pattison had made the quickest passage ever known, having been only eighty two days from the Lizard. There were no deaths and two children born on the passage.
Return to England
George Roberts returned to England on the Portland in April 1840.
He was employed as Surgeon on the Verona in 1842 ;