Seven of the 12 national award finalists are from Dunedin - four from the university and three from Otago Polytechnic.
Being named as one of the country's top tertiary teachers was ''incredibly special'' and a ''real honour'', Prof Ruru said.
It was also a ''huge acknowledgement'' of what she had been trying to do at the university over the past 15 years - promote indigenous perspectives in legal studies.
Prof Ruru said the law faculty and its senior leadership had been ''very supportive'' of her, and the overall southern track record of Tertiary Teaching Excellence Awards success had been ''great for Otago''.
Prof Ruru was New Zealand's first professor of law of Maori descent and the only Maori law faculty member at Otago since 1999, award organiser the National Centre for Tertiary Teaching Excellence said.
All 12 winners receive $20,000 and the supreme winner receives an extra $10,000.
The other Otago University award winners are senior teaching fellow in microbiology and immunology Dr Judith Bateup; Prof Darryl Tong, of oral diagnostics and surgical sciences; and senior lecturer in psychology Dr Rachel Zajac.
The Otago Polytechnic award winners are Institute of Sport and Adventure head of school Dr Megan Gibbons; architecture, building and engineering senior lecturer Matthew Thompson; and school of engineering principal lecturer Richard Nyhof.
Associate Prof Rhiannon Braund began the university's five-in-a-row run in 2012, followed by Associate Prof Gordon Sanderson, Dr Karyn Paringatai and Associate Prof Suzanne Pitama last year.
The university has won seven supreme teaching awards in the past 14 years, far more than any other New Zealand university.