The award is presented to schools and colleges that are able to demonstrate outstanding character education initiatives that have yielded positive results for pupil behaviour, citizenship, school culture and academic achievement.
Pupils and staff at Otago Girls' High School received the award at a special assembly yesterday.
It was no surprise those present were humble and gracious in their acceptance of the award.
Assistant principal Sue Lynch said the school's culture reflected its motto: Recti cultus pectora roborant - the right education makes the heart as strong as oak.
''This motto is reflected in our desire for girls to be the best they can be, in all aspects of their development; academic, sporting, cultural, social, spiritual and leadership,'' Ms Lynch said.
''High expectations are held for both behaviour and achievement, and our aim is to develop confident, resilient, independent and responsible young women who achieve success,'' she said.
The school can hold the award for four years.
New Zealand Foundation for Character Education deputy chairman and National Schools of Character selection panel convener Warwick Moyle said Otago Girls' High School had created a culture where there were high expectations for behaviour and achievement, and where pupils were encouraged to be involved in community service and to be good citizens, both within the school and out in the wider community.
He said it was significant Dunedin had three National Schools of Character.
In 2013, the award was won by King's High School and George Street Normal School.
Mr Moyle said character education in New Zealand schools had had nothing but positive outcomes.
The award will also be presented to Hamilton Boys' High School, Malfroy Primary School (Rotorua), Hato Paora College (Fielding) and Rathkeale College (Masterton) this week, as part of Character Counts Week (October 19-25).
