Īhāia Hūtana was born at Poroutāwhao, near Ōtaki, probably in 1843 or 1844. His parents had been taken there as captives by Ngāti Raukawa after a battle at Te Roto-a-Tara in Hawke's Bay. His mother was Te Ahiahi of Ngāti Te Whatu-i-apiti. In the genealogies recorded by the Native Land Court, his father is given as Te Hūtana Rangipūawhe (or Hūtana Pūawhe) of Ngāi Toroiwaho, a hapū of both Ngāti Kahungunu and Rangitāne descent with kin links to earlier Hawke's Bay descent groups. Te Hūtana Rangipūawhe also belonged to Ngāti Te Whatu-i-apiti.
While Te Hūtana may have still been alive in 1863, Īhāia's mother did not live long after his birth. She had kinship links to Ngāti Raukawa, and for her sake they permitted the young boy's relatives to take him back to Hawke's Bay. Recognised as one of the senior members of Ngāi Toroiwaho, he was settled by his aunt Kararaina at Ōruawharo, but when his Ngāi Tahu kin in Hawke's Bay heard he had returned, they took him to live at Takapau. About 1851 he moved to Waipukurau, but when the land he was living on was sold, he moved to Whenuahou to live with Ngāi Toroiwaho until he was old enough for his 'beard to be sprouting.'
Land sales had adversely affected Hūtana's people, and the grievances arising from the government's acquisition of the Aorangi block remained unsettled at the time of his death. The worst problems, however, stemmed from Hōri Niania Te Aroatua's sales in 1854. In 1864 Hūtana went to Pākōwhai to consult with Karaitiana Takamoana. He remained there to live, and in 1866 fought against the Hauhau under the command of Hēnare Tomoana and George Whitmore at Ōmarunui. In 1867 he spent five months on the East Coast, and later recorded that he greatly admired the good order and strong faith evident in the Māori villages he visited. He fought in the 1868–69 campaigns against Te Kooti. In 1867 he married Mereaira, a close relation of Hēnare Tomoana. They were to have three children: Hūtana Īhāia, Waiariki Rōpiha and Rerekohu Tūpaea. Although Mereaira died early, his kinship through marriage bound Īhāia closely to Tomoana.
Through this relationship Īhāia became involved in land issues and politics. He wrote letters to Te Wānanga, the newspaper published from 1874 to 1878 under the authority of Tomoana as the instrument of the Repudiation movement. His letters show him to be deeply religious (he was an Anglican) and to have an analytical intelligence capable of measuring the particular issues of the day against the broad context of New Zealand's past. In later years he was part of a group striving for the appointment of the first Māori Anglican bishop.
Īhāia also demonstrated his disillusionment with colonial land policy. In 1876 he spent four months on the East Coast, probably assisting Hēnare Tomoana to campaign for the return of his brother Karaitiana Takamoana as member of the House of Representatives for Eastern Māori. Īhāia recounted that, in contrast to his first visit into the territory of Ngāti Porou, dishonesty was prevalent; many had abandoned their faith in the church and were suffering from disease and poverty. These ills he attributed to the government and to the operation of the Native Land Court. He complained that the selection of owners to be grantees in the various blocks was entirely made by Rāpata Wahawaha, whose choices were biased and arbitrary.
From 1879 to 1884 Īhāia continued to assist Tomoana in his work as an MHR, acting as his secretary. In this capacity he accompanied Tomoana to Wellington. They habitually lodged in a boarding house, where Īhāia met his second wife who worked there. She was Sarah Alice Gaffney, who had been twice widowed and was originally from Dublin, Ireland. Alice (Arihi), as she was known, and Īhāia were to have one son, Hēnare Tomoana Hūtana.
During the 1880s Īhāia had personal experience of the land court during the protracted hearings in connection with the Waikōpiro block and others, which were originally reserves out of the Waipukurau block. In 1884 he was a member of the Hawke's Bay Native Committee which dealt with land and other matters. When called on to give evidence to the 1891 Native Land Laws Commission he said that Māori had held meetings for years to attempt to establish a scheme to resolve land problems, but that without the sanction of Parliament they had seen no results. He drew attention to the fact that the Native Equitable Owners Act 1886 had become a dead letter. This act would have given protection to beneficial owners against the tendency of grantees to use blocks as their personal property. He also drew the attention of the court to Crown failures in connection with the Waipukurau and Haowhenua blocks.
Īhāia was involved with the Kotahitanga movement, which chose Waipatu for the first meeting of its parliament in 1892. He was appointed organiser of nominations for the upper house, the Council of Paramount Chiefs. But his major work in support of the movement was as editor of the newspaper Huia Tangata Kotahi, printed in Hastings. Īhāia explained in the first and subsequent editions that its aim was to create unity among Māori by carrying to both islands news of their common misfortunes. It was intended to publish election results and the minutes of the Māori parliament sessions, and would also include news from abroad, and local news related to Europeans as well as Māori. Īhāia published the minutes and bills passed by Te Kauhanganui – the parliament of the Māori King, Tāwhiao; the proceedings of innumerable other Māori meetings and local organisations; and debates from the colonial Parliament. He also published letters recording births, baptisms, deaths and marriages, often including genealogies.
The first edition of Huia was published on 8 February 1893; it appeared fortnightly (weekly for a period) in 1893 and weekly in 1894. It was produced entirely in Māori, although in 1894 Īhāia reported persistent rumours that Europeans wanted to support the paper financially provided it was published in both languages. By 1894 it had run into financial difficulties. A scheme to finance it through a company with Māori shareholders also foundered. The last issue appeared on 9 February 1895. Īhāia, in his last editorial, explained that it was because of lack of means rather than lack of energy that the bird (the huia) would cease to fly.
Īhāia Hūtana's editorship of Huia Tangata Kotahi ensured his prominence as a national leader of Te Kotahitanga, and later, of many institutions affecting Ngāti Kahungunu. In 1898 he wrote to his paper's successor, Te Puke ki Hikurangi, reflecting on the performance of the Kotahitanga movement. He spoke of divisions within Te Kotahitanga and between tribes, and noted its failure to achieve mana motuhake (self-determination). He also discussed the negative response to the petition of 1897 asking that remaining Māori lands be reserved in perpetuity; it had been carried to Queen Victoria by the Māori contingent attending her diamond jubilee.
Īhāia was at the apex of his public life in the years after 1900. He went to Wellington to help put the Māori Councils Act 1900 into operation by drawing up by-laws and guidelines. He was chairman of the Tamatea Māori Council, established under the act, in 1901 and 1902. Also in 1901 he represented Ngāti Kahungunu at the reception for the duke and duchess of Cornwall and of York. On this occasion he was described as a 'tall, fine old chief…erect, [and] white bearded'. He worked with James Carroll in 1903 to settle Māori grievances at Kaikohe. In 1905 he sat on a royal commission which investigated Māori complaints that lands given for school trusts in Porirua, Ōtaki, Waikato, Wairarapa and Motueka were not being used for this purpose. From 1907 to 1914 he was an assessor in the Native Land Court, and he served on the Te Aute Trust Board from 1908 to 1915. An authority on things Māori, he was noted for his composing of music and haka, his oratory and writing. He was also known to make accurate predictions.
In 1914 Īhāia Hūtana retired to farm his lands, probably at Mataweka, near Waipāwa. He lived on for more than two decades, and died there, aged 94, on 9 November 1938 after an illness of six weeks. Messages of sympathy were sent by the prime minister, Michael Joseph Savage, and the minister of Māori affairs, Frank Langstone. Īhāia was buried on 12 November at the family burial place at Mataweka. He was survived by Arihi Hūtana, and by his children.