Although ministerial political advisors are prominent and influential actors within the core executive in Canada and elsewhere, information is scarce with respect to their personal and professional backgrounds and career trajectory. This article uses recent survey data and publicly available biographical information to analyse the demographic composition of senior ministerial policy advisors within the Government of Canada. It finds that, while ministerial policy staffers are young and politically committed, they are not so young nor so professionally inexperienced as sometimes thought. Nor are they always personally and tightly bound to their current ministers but often work for different ministers in different departments. This suggests that advisors are agents of the whole government as much as agents of their individual ministers and raises questions about the degree to which they are responsive to the Prime Minister's Office, thereby increasing centralization.