Ōtene Pītau is said to have been born in 1834 or 1835. His father, Thomas Halbert, was a trader of English descent who settled at Muriwai, Poverty Bay, with a woman of Te Aitanga-a-Mahaki named Pirihira Konekone. Pirihira became pregnant, and soon after quarrelled with Halbert and left him. She found refuge in the household of Ngāti Kaipoho leader, Tāmati Wāka Māngere, and later married a younger brother of Māngere, Pera Tawhiti. Sometime after her arrival she gave birth to a male child, who was adopted by Raharuhi Rukupō, another of Māngere's brothers, and given a family name, Pītau. He later acquired the name Ōtene, which was probably a baptismal name.
Raharuhi Rukupō became leader of Ngāti Kaipoho hapū of Rongowhakaata around 1840. He had a part-European adviser named Tom Jones, whose sister, Mere Whiti Hone, became Ōtene Pītau's wife. They apparently had no children but are said to have adopted Mere Tahatū and Heta Te Kani.
No record has been found of any involvement by Ōtene Pītau in the armed conflicts of the 1860s during which Rongowhakaata suffered considerable losses. In 1869 the Poverty Bay Commission granted title to land, excluding those who had fought against the Crown since 1863. Ōtene Pītau was included in the lists of names of owners for numerous blocks of land in which Ngāti Kaipoho, and in particular Raharuhi Rukupō, had interests. It seems that by this time Ōtene Pītau was Rukupō's designated ultimate successor. Raharuhi Rukupō died in 1873 and was succeeded by his brother Paora Kate, who had died by 1880. Ōtene Pītau, last of the Ngāti Kaipoho line, became leader.
Ōtene Pītau was one of the two influential chiefs of the Gisborne area, who were known as the last of the rangatira of Tūranganui. The other was Hēni Materoa Carroll of Ngāi Tāwhiri hapū of Rongowhakaata who succeeded her mother Riperata Kahutia in 1887. She was a very prominent leader whose life centred on Tūranga. Ōtene Pītau, on the other hand, lived at the southern end of Rongowhakaata land beyond the Waipaoa River estuary, and was conspicuous only within the tribe. He was significant for his contribution to the tribe in the period when its unity and standing were being restored following the destructive events of the 1860s.
By the 1880s Rongowhakaata was reviving, sub-tribe by sub-tribe. The revival was evidenced by the building of meeting houses. Ngāti Maru opened a meeting house called Te Mana-o-Tūranga at Manutūkē in 1883. To the north-east Riperata Kahutia was building a complex comprising a meeting house, church and dwelling house at her Awapuni land: the meeting house was called Te Poho-o-Materoa. These activities prompted Ōtene Pītau to initiate the construction of a large modern meeting house at Pākirikiri, which was called Te Poho-o-Rukupō to commemorate the name and work of Raharuhi Rukupō. It was opened in mid February 1887, and there was a large attendance at the opening ceremony. A day was devoted to discussion of issues, ranging from attitudes to Te Kooti to pre-election addresses by James Carroll and Ōtene Pītau's half-brother, Wī Pere. Ōtene Pītau voiced his opposition to the attempt by Te Kooti to revisit Poverty Bay in 1887, but stated his acceptance of Te Kooti's Ringatū followers. Te Poho-o-Rukupō was later moved to Manutūkē, where it still stands.
The tribal resurgence was matched by a revival of support for Anglicanism. At the opening of Te Poho-o-Rukupō, plans to build an Anglican church at Manutūkē were announced and commended by Ōtene Pītau. The church was to be for all Rongowhakaata, and was to incorporate the carved panels of the former Māori church which had been opened in 1863 but dismantled in a state of decay in 1881. The completed church, which had a fine stained glass window, was opened in 1890 on a site just to the west of the present church. Ōtene Pītau's contribution was recognised later by his appointment to the native church board of the diocese of Waiapu.
In 1894 Ōtene Pītau was host to the Kotahitanga parliament when it met at Pākirikiri. The large attendance became legendary; the meeting lasted for well over a month. Ōtene Pītau became a member of the Tai Rāwhiti District Māori Land Council in 1903. In 1906 he was appointed an advisory counsellor for the Takitimu Māori Council and the same year was one of the representatives from the East Coast who joined Māori from throughout New Zealand at the funeral of Premier Richard Seddon.
Ōtene Pītau was by then over 70 years old but his greatest achievement as leader of Rongowhakaata still lay ahead. The church which opened at Manutūkē in 1890 was destroyed by fire in 1910. The diocese had fortunately insured the building and so reconstruction began. In late 1912 Ōtene Pītau placed a full-page advertisement in the Māori Anglican journal, Te Pīpīwharauroa, to invite all to a hui for the opening of the new church on Sunday, 9 March 1913. Enormous crowds began to gather at Manutūkē on 5 March. Knowing that there would be Māori representation from many parts of New Zealand, the Reform government used the occasion to promote the idea of assimilation of the Māori race with the European. The native minister, W. H. Herries, spoke at length on this matter and on land policy. Māui Pōmare, James Carroll and Apirana Ngata were also in attendance.
Ōtene Pītau lived for another eight years after the church opening. He died at Manutūkē on 13 August 1921.