Born in St. John's, October 17, 1814, Hoyles was the son of Newman Hoyles, the first leader of the Tory Party in Newfoundland and became the first Newfoundland born Premier. Hoyles at first opposed "responsible government", as his father at first opposed Representative government. He led the largely Protestant Conservative Party in 1855 but failed to win the election. He also lost the 1859 election including his own seat.
In 1861, Hoyles was hired by senior judges to fight PremierJohn Kent's plans to reduce their salaries. When Kent accused the judges, the governor and the Conservatives of conspiracy the Governor fired Kent and appointed Hoyles the new Premier. Hoyles government was defeated in the legislature and had to fight an election in a highly charged sectarian atmosphere which resulted in riots when the Conservatives won the election.
During his administration, he tried to cool down sectarian tensions between Catholics and Protestants. He also sent delegates to the Canadian Confederation Conference at Charlottetown in 1864. Those delegates, Ambroise Shea and Frederick Carter, did not have the power to negotiate.
Hoyles decided to leave office in 1865. He was succeded by Sir Frederick Carter. Hoyles was appointed Chief Justice of Newfoundland serving in that position from 1865 until 1870. He then retired to Halifax where he resumed his mercantile operations. This is where he passed away on February 1, 1888