Frederick Joseph Moss was born at Longwood, St Helena, probably in 1827 or 1828. He was the son of Sarah Britton and her husband, a farmer whose first name is unknown. Frederick was educated at the head school of the East India Company (which then administered the island), and at the age of 12 or 13 was sent to work in his uncle's business at Port Elizabeth, South Africa. As a young man Frederick volunteered for service in the Cape frontier war. He returned to St Helena to work for his father in 1847, and probably in 1853 or 1854 he married Emily Ann Carew. In 1857 he revisited South Africa, intending to settle in Natal. However, agricultural prospects having been destroyed by locusts, he decided to emigrate to New Zealand.
With Emily and their three children Moss arrived at Lyttelton on the Zealandia on 12 November 1859. He immediately established a substantial business as a merchant, selling goods ranging from pianos and liquor, to saddlery, chiffoniers and zinc nails. In Lyttelton Moss supported proposals for the construction of a tunnel to Christchurch and took a leading role in the formation of a volunteer company, said to be the first in the South Island, and was elected captain.
Early in 1862, following the discovery of gold in Otago, Moss sold his business and moved to Dunedin. He became involved in a number of business ventures in Otago and Southland, the most important being a partnership with Thomas Dick, a prominent Otago politician. Moss also became captain of the Dunedin Rifle Volunteers, and in July 1864 founded the Otago Daily Mail which he sold three months later to J. A. Torrance.
In May 1863 Moss was elected to the Otago Provincial Council as a representative for City of Dunedin. He served as secretary for public works and as provincial treasurer. He assumed office at a time of financial crisis caused by the refusal of London bankers to approve provincial loans, and Moss did much to reduce government expenditure and to set Otago's finances on a sounder footing. His major achievement came in 1865 with a plan for the construction and financing of Otago railways. During his time in provincial politics he was closely associated with Dick, his business partner, and was an opponent of Julius Vogel. The executive in which Moss served lost office to Vogel in November 1866, and Moss resigned from the council early in the following year.
The blockade of the Confederate States of America in the mid 1860s caused world cotton prices to rise, and Moss joined a group of prospective planters on a voyage to Fiji early in 1868. He bought land above Navuso on the Rewa River in south-eastern Viti Levu where, in partnership with his brother-in-law, he tried to establish a plantation. After a set-back caused by a hurricane in March 1869, and the collapse of his own health, Moss returned to New Zealand later that year. He worked first as a leader writer for the New Zealand Herald, and then as a temporary employee with the Auckland provincial treasury. This position was concerned partly with the establishment of public schools, and led to his appointment as the first secretary of the Auckland provincial Board of Education.
Moss was elected to the House of Representatives in February 1878 representing Parnell. Throughout his parliamentary career, he was a liberal and a strong supporter of Sir George Grey. He defended provincial interests against the central government, and supported protection and the introduction of triennial parliaments. He favoured the introduction of manhood suffrage but opposed female suffrage. Moss constantly sought a reduction in government expenditure, and opposed general loans for public works, arguing that all borrowing should be for specific projects approved in advance. He toured the Pacific islands for several months in 1886 and was associated with Vogel's plans for an island confederation with New Zealand at its centre.
In 1889, after the Cook Islands had become a British protectorate, it was agreed that the New Zealand government, which was to meet the costs of administration, could nominate the British Resident to head the government. Moss was appointed in 1890 and resigned his seat in Parliament, leaving behind him the prospect of a cabinet portfolio in the ministry soon to be formed by John Ballance. Moss believed that the demoralisation of the indigenous people in the Pacific islands was largely caused by the failure of Europeans to treat islanders as equals. He therefore established island governments and a federal council, and tried to involve Cook Islanders in both policy making and administration. He emphasised the importance of education and placed particular stress on the teaching of English in the public schools that were established from 1896. These policies, and his condemnatory attitude towards many of the local Europeans, made him many enemies and the consequent dissension contributed to the decline of his health in the late 1890s.
Moss's mishandling of the introduction of a Federal Court Bill that would have substantially increased the Resident's power brought together his European and Cook Islands opponents and led to calls for his removal. In a formal inquiry Sir James Prendergast, the New Zealand chief justice, largely vindicated Moss but concluded that his position in Rarotonga was no longer tenable, and he was recalled.
When the Cook Islands were annexed to New Zealand in 1901, Moss condemned the move, partly because his progressive views on colonial administration led him to favour self-government for island peoples. He also opposed the mooted annexation of Fiji because it implied 'abandonment of our proud boast of keeping New Zealand as a White Man's Country'.
On returning from the Cook Islands in September 1898 Moss again took up residence in his house in Parnell, where he spent much of his embittered retirement writing to newspapers (often defending his own role in the Cook Islands) and contributing to periodicals. A prolific writer, his more important works include A planter's experience in Fiji (1869); Through atolls and islands in the great south sea (1889); A school history of New Zealand (1889); and Notes on political economy from the colonial point of view (1897). He was a prominent Freemason and a vestryman at St Mary's Anglican Cathedral in Parnell.
When he died at Auckland on 8 July 1904, Frederick Moss was survived by his wife, who died in 1906, and by six of their eight children. For nearly 40 years he had been a prominent voice in New Zealand politics and he had played a key role in developing New Zealand's perceptions of, and policies toward, the Pacific islands.