Paratene Ngata was born at Ahikouka, near Waiomatatini, on the East Coast, possibly in September 1849. His father was Wiremu Karaka Te Ito, of Reporua, and his mother was Hera Te Ihi, known also as Ruataupare. He was related to Te Whanau-a-Te-Ao, Ngati Rangi and Te Whanau-a-Karuai hapu of Ngati Porou. Paratene Ngata grew up in the household of Rapata Wahawaha, whose wife, Harata Te Ihi, was his mother's younger sister. He married Katerina Naki and they had two children; the elder, and most famous, child of the marriage was Apirana Ngata. Apirana was not, however, Paratene's first child. This was Hone Te Ihi Ngata, whose mother was Harata Pokiha.
As a child Paratene attended William Williams's mission school at Waerenga-a-hika, near Turanga (Gisborne), which was closed in 1865, as the Pai Marire movement gained strength. Paratene accompanied Rapata during the East Coast wars and saw action against Hauhau forces. In June 1869 he was recruited into the Armed Constabulary No 9 division (Ngati Porou), and, with Te Hatiwira Te Houkamau and Peneamine Tuhaka, led a company of Ngati Porou soldiers to Taranaki for the campaign against Titokowaru. The company was taken by steamer to Wanganui and marched from there to Patea. However, fighting had ceased before their arrival and there were no further operations against Titokowaru. It is probable that this Ngati Porou contingent returned to the East Coast and took part in the campaigns against Te Kooti.
After the wars Paratene kept a store (with accommodation for Europeans) at Te Kawakawa (Te Araroa), and a hotel at Waipiro Bay, and supervised the Waiomatatini sheep station, established by Rapata. Ngati Porou had learned sheep farming while working for European farmers, and used their wages and rents from leased lands to establish their own co-operative sheep stations. Between 1886 and 1891 the number of sheep owned by Maori on the East Coast grew rapidly.
Paratene also worked as an assessor on the Native Land Court, in the King Country and at Taupo; he was involved in the investigation of the Rohepotae block of 1,636,000 acres, which had some 4,500 Maori owners. It was surveyed and awarded to individual owners by the court. This was done against the strenuous opposition of the King movement, which did not want the land removed from the King's mana by coming under Pakeha law. Individual title was also against the wishes of Ngati Maniapoto, who wanted the land awarded to the claimant tribes and hapu, to preserve tribal society and prevent individual land sales. But the court had no power to do this and after much delay the names of the individual claimants were sent to the court for adjudication and registration. The proceedings of the court were quiet and orderly, owing to the respect in which Paratene Ngata and the judge, William Mair, were held. In addition, agreement was gained through the court for the railway line to pass through the block, and 635 acres were set aside for it. As the King's supporters had previously been able to prevent the progress of roads and railways, it was clear that the movement's influence was waning. At various times after 1870 Paratene also took part in title investigations of large blocks of Maori land in the Thames, Hawke's Bay, Wairarapa and East Coast districts.
In 1891 Paratene Ngata gave evidence to the parliamentary commission appointed to inquire into native land laws. He said that when land with many owners was granted to 10 trustees, in accordance with the Native Lands Act 1873, a government officer should be appointed to ensure that rents and proceeds from land sales were fairly distributed. He thought that for each block a committee should be set up and empowered by Parliament to carry out all transactions and to reserve land for the Maori to farm themselves. He favoured government loans to Maori farmers to improve their land, and he argued that this would be for the general prosperity of the country. He criticised the land court as too expensive and said its sittings should be held in the vicinity of the land which was being adjudicated; Maori people suffered great hardship when forced to leave their homes and reside in the midst of Europeans in order to attend the court.
In his proposed reforms Paratene Ngata was supporting the movement for Maori self-rule; committees were already providing local government and law enforcement in Maori areas, but they had no legal authority. Like other Maori leaders of the time, such as Paora Tuhaere of Ngati Whatua and Horonuku Te Heuheu Tukino IV of Ngati Tuwharetoa, Paratene wanted Maori committees to have the power to adjudicate land ownership, and the legal authority to try minor cases and enforce school attendance. The informal powers of existing committees, based on respect for chiefs and elders, were declining as land became individualised. Paratene argued that if the committees could not be given legal standing, then native assessors should be given the power to decide cases of land title where no difficulties were involved and where they had no interest themselves. Only major cases, or ones with difficulties, should go to the expensive and time-consuming Native Land Court.
Paratene Ngata unsuccessfully contested the 1894 election for Eastern Maori against Wi Pere, a leader of Rongowhakaata and Te Aitanga-a-Mahaki. From 1904 he lived permanently at his home at Waiomatatini, and took a prominent part in promoting schemes for the incorporation of Ngati Porou land to provide better organisation and financial assistance for farming. He was chairman of the Horouta Maori Council and of the Waiomatatini School Committee. He worked for the improvement of marae and was an expert on the traditions of his people. He was a keen educationalist, although he criticised Te Aute College graduates for being absorbed into the commercial life of Gisborne and not giving leadership to the rural communities.
Like most of the leading men of Ngati Porou, Paratene adhered to the Anglican church. It is said, however, that he and his wife, Katerina, made use of traditional rituals in order to conceive their first child, Apirana. Paratene was unsympathetic to other religious groups, especially the Church of Jesus Christ of Latter Day Saints. When Mormon missionaries first arrived in the Waiapu district, they were thrown into the river. Nevertheless they were able to open a place of worship at Tikitiki in 1891. Paratene also convened a meeting to discuss whether people of the Ringatu faith should be allowed to hold services in the district.
Throughout his long life Paratene Ngata was leader of his people. He fostered their survival by encouraging economic, political and educational development. This spirit he inherited from leaders such as Rapata Wahawaha, and transmitted it to his son Apirana, who was to lead Ngati Porou in the first half of the twentieth century. Paratene died on 15 December 1924, and is buried in the family cemetery on Puputai hill at Waiomatatini.