At present, Mrs Nicholson is principal of St Peter's College in Gore, and will join Kavanagh on September 2.
She has worked at a range of co-educational schools in Southland and Wellington, and has been the Southland Rural Principals' Association chairwoman and the Eastern Southland Kahui Ako support principal.
Kavanagh College board of trustees chairman Trevor Thomson said
Mrs Nicholson had led significant change in curriculum, in the development of contemporary teaching practices and in the effective, balanced use of digital technologies.
"Her skill set is underpinned by her strong, inclusive Catholic faith and by her commitment to social justice and action.
"She will be able to build on the work of the late Tracy O'Brien in enhancing the supportive and positive environment at the college."
Mrs Nicholson, who has been principal of St Peter's College since 2014, said she was looking forward to the move to Dunedin.
"I have truly enjoyed the privilege of leading St Peter's College, and after many years of raising a family in Eastern Southland, my family and I are looking forward to making Dunedin our home."
Mr Thomson said acting principal Steve Read would continue to lead the college until Mrs Nicholson arrived in September.
Mrs Nicholson went to Villa Maria College, Christchurch, from 1981 to 1985 and has a bachelor of horticultural science degree from Lincoln University.
She has a diploma of teaching (special needs) from the Christchurch College of Education and began at Gore High School in 2003, initially as a science and biology teacher.
