Maria Coate taught at a variety of secondary schools and held leadership positions at Willetton Senior High School, St Mary's Anglican School for Girls, Presbyterian Ladies' College, All Saints' College and St Andrew's Grammar. She also wrote three economics texts and was president of The Economics Teachers Association of WA. Ms Coate taught Modern Greek for the Hellenic Community of WA in their after-school language and cultural programme, as well as tertiary level Economics at Curtin University's School of Business. She became principal of the International School of Western Australia in January 2015. In November 2019, Ms Coate took a period of leave from her role while the school is being investigated over alleged bullying issues. It was decided in December 2019 that she will not be returning to her role.