Tom McMillin holds a bachelor's degree in economics and accounting from the University of Michigan, obtained in 1987. He began his career as a certified public accountant, working in this capacity until 2009. McMillin has held various public sector roles, including serving as mayor of Auburn Hills and a member of the Oakland County Commission. He spent five years as a member of the Michigan State House, representing the 45th State House district. McMillin has been actively involved in conservative policy advocacy, notably opposing tax increases and supporting traditional marriage definitions. Currently, he serves on the Michigan State Board of Education.

Tom McMillin's political identity is marked by a steadfast opposition to tax increases and traditional conservative stances on social issues. His role as honorary chairman of Concerned Taxpayers of Michigan underscores his commitment to fiscal conservatism. McMillin's support for defining marriage as a union between a man and a woman and his opposition to a gay rights ordinance in Royal Oak in 2009 reveal a socially conservative streak. These positions, however, coexist with an unexpected convergence on environmental regulations with opposing factions, suggesting a highly localized approach to policymaking that balances regional industrial interests.