Nga Tawa was founded in 1891 in Shannon, and later moved to Marton where it was purchased by the Wellington Diocese of the Anglican Church in 1912. The established Wellington Diocesan School was an autonomous body, having the Bishop of Wellington an ex officio member of the Board of Trustees.

Nga Tawa has continued to operate as a boarding and day school for students catering for the needs of families throughout New Zealand and internationally, wanting a challenging Anglican Secondary education in a rural setting. The school atmosphere emphasises Christian standards, values and observance. Integral to this education is the use of the Chapel as a place of regular prayer, worship and instruction.

In 2008, Nga Tawa Diocesan School became the school’s official Ministry of Education name.

It has been the policy of the School, under the Integration Agreement, to accept only a limited number of day students on the clear understanding that such students will as far as possible follow the routine and share in the activities of boarding students.

In addition to the educational philosophy outlined above, the Special Character provisions of the Integration Agreement require that the School places a particular emphasis on Music, the Arts and Recreation.