This article analyses the relationship between impostor phenomenon and motivation in academic women. These highly successful academics often express feelings of self-doubt, lack of belongingness, and incompetence, ideas echoed within motivation literature. This project establishes IP prevalence within 1,326 self-identified academic women and examines the relationship between IP and motivation (operationalized by measures from Expectancy-Value Theory, Attribution Theory, and Self-Determination Theory). Findings indicate elevated levels of IP amongst our female academic sample. Statistically significant relationships were observed between IP and measures of motivation, including negative relationships between IP and sense of relatedness, as well as IP and attributions of success and failure. Results also indicate a combination of feelings of competence and relatedness, attributions to luck, ability, ease, and effort, and both cost and utility values predict 57.6% of the variance in IP sum score. Implications for graduate and early career supports, as well as systemic and cultural changes are discussed.