Richard (Dicky) Barrett's date and place of birth, and his parents' names, are unknown. It is possible that he was born in Durham or London, in England. His colourful, readable journal and his connection in Durham with the family of William Fox, later premier of New Zealand, throw doubt on the assumption that he lacked education and polish. He sailed from Rotherhithe at the age of 16 as a crewmember on a trading ship.
After four years' trading in the Pacific, Barrett had become mate and shareholder in the 60 ton schooner Adventure, which in 1828 he and Captain Jacky Love brought to New Zealand, expecting less commercial competition than elsewhere. Their trading was typical – clothes and blankets, muskets and powder, tobacco, razors and rum, barley and corn, loaded in Sydney, were discharged into their storehouses at Kororāreka (Russell), Queen Charlotte Sound and Port Nicholson (Wellington). The goods were bartered for pigs, flax and potatoes, which were sold in Sydney.
Barrett's connection with Te Āti Awa of Taranaki began when two canoes paddled by 40 warriors and commanded by the Te Āti Awa leaders Hōniana Te Puni-kōkopu and Te Wharepōuri, expressly on the lookout for a trader on the Sydney run, intercepted the Adventure near Cook Strait on its second trans-Tasman voyage. Fearing their traditional enemies, Waikato, Te Āti Awa considered that their survival depended on an association with Europeans who could supply arms. Barrett, fluent and fearless and a shrewd trader, keen to expand his connections, inspected flax and pigs at Ngāmotu, at present day New Plymouth, and Te Āti Awa, pressing for a trading post permanently occupied by Pākehā to ensure both prosperity and preservation, presented Māori wives to him and Love. In 1828 Barrett married Wakaiwa Rāwinia (Lavinia), or Rangi, grand-daughter of Tautara, niece of Te Puni and sister of Te Wharepōuri. A Christian marriage service was performed at Ngāmotu on 28 March 1841, when the Wesleyan missionary Charles Creed first visited Taranaki.
The Adventure was named the Tohora and Barrett became Tiki Parete. He was not, however, absorbed into the pā and dependent on the tribe; his equality in the association with Te Āti Awa was uncommon for the 1820s. He built houses, dressed his daughters in European dresses, supervised crop farming, extended flax plantations and engaged in trade with the Sydney market. The Adventure was wrecked at her moorings at Ngāmotu after a return voyage from the Sydney market in May 1828, and Barrett sold its cargo to a passing English trader; this was the first direct shipment of goods from Taranaki to England.
The English trader warned of a Waikato raid and the invasion came in 1831–32. After the siege and capture by Waikato of Pukerangiora, Te Āti Awa withdrew to Ōtaka pā, Ngāmotu. Behind emergency earthworks and palisades, outnumbered, overcrowded and suffering food and water shortages, they withstood the siege, and the mana of Barrett and Love was greatly increased. Love had first sighted the invading canoes, and Barrett's decoy attack had exposed Waikato to cannon fire from guns salvaged from the Adventure. Victorious but fearing reprisals, Te Āti Awa abandoned the villages and cultivations of their homeland and trekked overland, with Barrett, to Port Nicholson.
Barrett continued to trade, buying a new schooner, building a raupō warehouse and importing farm implements and whaling gear; he then established a whaling station in Queen Charlotte Sound. When, in August 1839, the Tory arrived with the first New Zealand Company settlers, Barrett was engaged by Colonel William Wakefield as an interpreter, and piloted the ship to Pito-one (Petone). He was able to overcome resistance to land selling, negotiating the sale of land at Port Nicholson, Queen Charlotte Sound and Taranaki. Many of these purchases were subsequently disallowed by government land claims commissioners.
With the purchases accomplished, Barrett gave land and timber for a courthouse in Port Nicholson, offered employment to settlers and engaged a skilled tanner and brewer to develop his business enterprises in the new colony. He suggested that barrister William Fox be persuaded to emigrate to help settle land claims. Company gratitude was expressed in a bonus to establish Barrett's Hotel, the civic centre of Wellington until it was taken over for government offices in 1849. When losses in whaling deprived him of his hotel in 1841, he led a party of Te Āti Awa back to Taranaki. There he helped establish settlers in New Plymouth and began cattle farming, while his boats chased whales and transported flax to Port Nicholson.
Dicky Barrett died on 23 February 1847 after a whaling accident, and was buried in Wahitapu cemetery in New Plymouth, beside his daughter Mary. He was survived by two daughters, Caroline and Sarah, an adopted son, and his wife, Rāwinia, who died in 1848. The image of this convivial English trader has lived on in Wellington folklore for a century and a half in the names of Barrett Reef and Barrett's Hotel.