Carmel Sepuloni was born, raised and schooled in Waitara, Taranaki. Her father was a Samoan-Tongan migrant freezing worker and 'staunch unionist' and her mother was a Pākehā from a conservative farming family.

She moved to Auckland in 1996 to study towards teaching qualifications becoming a teacher and gaining experience in Samoa and with Auckland youth in alternative education programmes; an equity manager; and a research project manager in Pacific health at the University of Auckland.

Much of Carmel’s work as a Member of Parliament has been focused on improving educational and health outcomes for marginalised and vulnerable groups.