Henry Halloran spent his childhood in England. His family came to Australia in 1822 to join his father, Laurence Hynes Halloran (q.v.), who had been transported to the Colony for forgery in 1819. His father later ran one of Sydney's first Grammar schools.
Halloran worked for many years in the New South Wales civil service, holding the positions of chief clerk in the Survey Department and under-secretary of the Colonial Secretary's Department. After his retirement in 1878, he was made a Companion of the Order of St Michael and St George.
Halloran was active in the literary community of Sydney, and mentored younger writers, including Henry Kendall. He was a prolific contributor to colonial newspapers and magazines, and he also translated Anacreon's poems from the Greek.