Nō te 8 o Ākuhata o te tau 1919 i whānau ai a Hōri Mahue Ngata i te kāinga o tana tupuna, o Apirana Ngata, i ‘The Bungalow’ i Waiomatatini. Ko tana pāpā ko Mākarini Tānara Ngata, he tangata ahu whenua, ko ia rā te mea mātāmua o ngā tamariki a Apirana; ko tōna kōkā ko Maraea Mereana Baker. I te matenga o tana pāpā i te tau 1929, ka moe tāne anō tana kōkā. I raro i tēneki o ōna īngoa, o Maraea Te Kawa, ka riro i a ia te tūranga tumuaki o te Rōpū Wāhine Toko i te Ora (Māori Women’s Welfare League). Ko ngā kārangarangatanga o Hōri ko Te Whānau-a-Karuai, ko Te Whānau-a-Rākairoa me Te Aitanga-a-Mate, he hapū katoa ēnei nō Ngāti Porou. He tātai hono anō ōna ki a Ngāti Rongomaiwahine me Ngāti Rākaipaaka o Nūhaka me Te Māhia, tae atu ki a Rongowhakaata me Ngāi Tāmanuhiri o te takiwā o Tūranga (Gisborne).
I kuraina a Hōri Ngata i te kura Māori o Waiomatatini me te Kāreti o Te Aute. I te mutunga o tana kura ka haere ia hai tauira ahu whenua i Horoera, i raro i ngā parirau o Hēnare Dewes tohutohungia ai, ā, i muri iho ka riro a ia nā Reupene Pāhau Milner i ako i te teihana o Whāngārā i te raki o Tūranga. I te 25 o Maehe i te tau 1940 ka moea e ia a Mihihara Whakaara Ngārimu i te whare karakia Mihingare o Pita te Kaikauhau (St Peter’s Anglican Church), i Whareponga. Ko ngā minita i mārena i a rāua ko Poihipi Kōhere rāua ko Tūroa Pōhatu. Hai tuahine a Mihihara ki a Te Moananui-a-Kiwa Ngārimu, i whakawahia rā ki te tohu toa, ki te Rīpeka Wikitōria (Victoria Cross). I noho rāua i Pōhatukura i te kāinga o te whānau o ngā Ngārimu i Ruatōria (Rua-a-Tōrea rānei), kātahi ka neke atu ki Te Pahī e pātata rā ki Te Puia, ka noho i reira, hea miraka kau ai te mahi.
Nō te 18 o Mei o te tau 1941, i Ruatōria, i haina a Hōri ki te haere ki te Pakanga Tuarua o te Ao. I uru a ia ki te Ope Taua 28 (Māori) o Aotearoa (28th New Zealand (Māori) Battalion), ka haere nei ki te pakanga i Īhipa, ā, nō muri iho i whakawhiti atu ia ki te kauhanga riri i Itari, i raro i te whakahaere o Kānara Arapeta Awatere. Riro ana i a ia te tūranga āpiha matataua me tērā o te rūtene, ā, ka taka nei ki te tau 1946 ka hoki mai nei ia ki te kāinga.
Nō te hokinga mai, ka mahi pāmu ia i Pōhatukura taka atu ki te tīmatanga o te tau 1947, kātahi ka hūnuku atu ai ki Māngere i Ākarana (Auckland) ki te puni mō ngā kaimahi Māori (Māngere Māori Workers’ Camp). Meinga ana ko tana pāpā whakaangi, ko Nōpera Te Kawa te kaiwhakahaere i reira, me tana kōkā, me Maraea te kaitaka kai. I noho a Hōri ki te toa mahi rerewē i Ōtāhuhu mahi ai tae noa ki te tau 1954; ka mate nei a Nōpera ka riro i a Hōri te tūnga kaiwhakahaere. I noho tonu a Hōri hai kaiwhakahaere ā tae noa ki te katinga i te Tari mō ngā Take Mahi (Department of Labour) i taua puni i te tau 1957. Kātahi ka whakawhiti atu ia ki te wāhanga kaute o te Tari Kura (Department of Education). I Pakuranga rātau ko tana whānau e noho ana. I taua wā, hamanga haere ai te ako a Hōri i ngā mahi kaute.
Nō te tau 1960 i whakauru atu a ia hai tauira o te mātauranga Māori ki te whare wānanga o Tāmaki-makau-rau (University of Auckland). Atu i te tau 1962 i noho ia hai pūkenga hamanga mō te mātauranga Māori, e iwa tau i pau i a ia ki tēnei tūranga. I te tau 1965, ka riro mai i a ia tana raihana kaiwhakamāori, ka kite ia i te take e hiahiatia ai tētahi pukapuka taki kupu, e āhei ai ngā tauira te whakamāori i ngā kōrero mai i te reo Ingarihi ki te reo Māori. Nō te nukuhanga atu o ngā akoranga i te mātauranga Māori ki te taumata tuatoru i te tau 1966, ka whakaurua atu ai te mahi whakamāori i ngā whakaaetanga ā-pukapuka ki roto i te marau mātauranga. Kāore anō kia mahia noatia he pukapuka tōtika, whakamārama kupu atu i te reo Ingarihi ki te reo Māori, te take i tahuri ai a Hōri ki te hanga i tāna ake tuhinga ā-ringa hai tauira mō te whakamāori i ngā kupu ture. Taihoa ake tēnei hai pūtake mō tana pukapuka taki kupu mai i te reo Ingarihi ki te reo Māori. Āta wehewehea rawatia e ia ana hāora tina me te nuinga o ngā Rātapu hai wā mahi māna i te rārangi kupu. E rua tekau mā ono tau i pau i a ia e whakahiato ana i ngā kupu mai i ngā wāhi katoa, arā, i Ngā mōteatea , i te Paipera Māori, me ētahi atu kōrerorero noa o te reo Māori. Ka noho tēnei hai tikanga mahi māna, ka hoki atu nei rāua ko Mihihara i te tau 1979 ki Ruatōria whakatā ai.
E hia nei ngā tau e kōharatia ana e ia te tākaro nei, te korowha, manako tonu kia toa ia ki te kaute korekore. Kore rawa tēnei i tutuki i a ia, ka mutu e toru nei tana utanga. He mema ia nō te karapu korowha o Grange i Papatoetoe me te karapu o Kāwhia.
I Ruatōria, ka eke a Hōri ki te Kaunihera ā-Rohe o Waiapu, noho ake hoki i runga i ngā komiti marae maha, ka kitea nei te painga o ana pūmanawa kaute. He kaha ia ki te akiaki i te rangatahi kia aro nui ki te whai i te mātauranga, kai reira anō hoki ia e hono mōhū ana i te mahi whakapiri o te Pākehā rāua ko te Māori, whakahau hoki i te kōrero punenga. Tāpiri atu ki ngā āwhina mai o tana wahine, o ana hoa me tōna whānau i haere tonu tana mahi i tana pukapuka, ā, tīmata noa ngā mahi ētita i te tau 1980 i raro i te whakahaere a Hōne Apanui. Whakaarahia ake ana te Komiti Arohi, hai rōpū mahi, tokoono nei ngā tāngata hai āwhina i a ia ki tana tuhinga ā-ringa. I tū ngā hui a tēnei komiti ki Ruatōria, ki Wharekahika, ki Pōneke, ki Ākarana, ā, i ētahi wā i haerea aua hui e ngā kaumātua, uru rawa atu hoki ki ngā mahi. Nō te tau 1993, e whā tau i muri mai o tōna matenga atu, ka oti tana pukapuka, arā, te English–Māori Dictionary.
I mate a Hōri Ngata ki Ruatōria i te 15 o Pēpuere i te tau 1989, ā, mahue mai ana ko tana wahine rāua ko tā rāua tama, ko ngā mokopuna tokotoru. Kei te urupā o Tūrangarāhui ia e tanu ana, kāore i tawhiti atu i Pōhatukura, i te wāhi i noho ai rāua ko tana wahine i tō rāua moetanga.