Saint Helena has a small population of about 4,250 inhabitants, mainly descended from people from Britain – settlers (“planters”) and soldiers - and slaves who were brought there from the beginning of settlement – initially from Africa (Cape Verde Islands, Gold Coast and West Coast of Africa are mentioned in early records), then India, Madagascar, over the years until the planters felt there were too many and no new slaves were imported after 1792. The island was first settled by the British in 1659. In 1840 St. Helena became the Centre for the British West Africa Squadron, preventing slavery to Brazil mainly and many thousands were freed on the island. These were all African, and about 500 stayed there while the rest were sent on to the West Indies and Cape Town, and eventually to Sierra Leone.

Imported Chinese labourers arrived in 1810, reaching a peak of 618 in 1818, after which numbers were reduced, and only a few older men remained after the Crown took over in 1834, when the majority of those still here were sent back to China, although records in the Cape suggest that they never got any further than Cape Town. There were also a very few Indian Lascars who worked under the harbour master.

Christianity has deep roots in St Helena and has played a symbolic part in the island's community, the majority of people belonging to the Church of England, being members of the Diocese of St Helena, which includes Ascension Island, and which has its own Bishop residing on St Helena. The 150th Anniversary of the Diocese was celebrated in June 2009. Other denominations of Christianity represented on the island for many years are: Roman Catholic (since 1852), Salvation Army (since 1886), Baptist (since 1845), and in more recent times; Seventh Day Adventist (since 1949), Jehovah's Witness and New Apostolic. The Baha'i Faith has also been represented on the island since 1954.

Tristan da Cunha, settled since 1815, has a population of fewer than three hundred inhabitants of mainly British, Italian and St. Helenian descent. Christianity is the main religion, mainly Anglican and some Roman Catholic.

Ascension Island has no native inhabitants. It is a working island with a transient population of approximately 1,000, made up mainly of members of the American and British militaries supporting civilian contractors who serve on the joint Anglo-American airbase, and members of their families (a few of whom were born on the island), also Cable and Wireless and local Government employees.

The citizens of Saint Helena hold British Overseas Territories citizenship. On 21 May 2002, they were granted access to full British citizenship by the British Overseas Territories Act 2002. Also see British nationality law. During periods of unemployment, there has been a long pattern of emigration from the island since the post-Napoleonic period. The majority of Saints emigrated to the UK, South Africa, and in the early years, Australia. Nowadays many go to work on Ascension, the Falklands (only since the Falklands war) and UK. Saint Helena is one of the few territories in the world which has never had a recorded HIV / AIDS case.