Her research students described her as an encourager, consistently supportive and having an ''interesting, intelligent, experienced academic mind, with a wealth of knowledge''.
''I always leave her office feeling energised and ready to tackle my work anew,'' one student said.
The annual supervisor of the year awards attracted about 200 nominations and 12 supervisors were short-listed as finalists.
''I'm absolutely thrilled,'' Prof Fitzgerald said.
It was also ''quite humbling'' that her postgraduate students had taken the trouble of nominating her.
The award also reflected wider teamwork and collaboration, including among her colleagues in the Otago anthropology and archaeology department.
And the award was ''shared'' with her postgraduate students, because research supervision was ''about both of us making the best of that relationship,'' she said.
Prof Fitzgerald also won the humanities divisional award.
The title of best new supervisor of the year was awarded to Dr Prasad Nishtala, of the Otago School of Pharmacy, at a function on campus this week.
One of his students paid tribute to ''everything he has and continues to give his lucky students''.
Other divisional winners were geology lecturer Dr James Scott, science; Curekids Professor of Paediatric Genetics Prof Stephen Robertson, health science; and Associate Prof Holger Regenbrecht, of information science, who won the commerce award for the second year in a row.
A special award acknowledged the ''amazing work'' done by the late Prof Jules Kieser, inaugural director of the Sir John Walsh Research Institute, for his thesis candidates over the years.
Prof Kieser was a finalist in the awards in 2011, 2012 and 2013.
Otago Graduate Research School manager Claire Gallop said Prof Kieser was well respected for his expertise, but also ''loved for his kindness, his generosity and his naughty sense of humour''.
The supervisors are nominated and voted for by students.
Other divisional finalists were. -Sciences: Prof Robert Poulin, zoology, Dr Rachel Brown, human nutrition. Health sciences, Dr Christine Jasoni, anatomy. Commerce: Prof Juergen Gnoth, marketing; Dr Jodyanne Kirkwood, management. Humanities: Dr Douglas Hill, geography; Dr Melanie Beres, sociology, gender and social work.