Shirley Hoy was appointed Acting Chief Administrative Officer and Acting Chief Financial Officer for the City of Toronto on June 27, 2001. Shirley Hoy was appointed Chief Administrative Officer for the City of Toronto on November 6, 2001. Her title was changed to City Manager on April 15, 2005 as part of a reorganization of the City's administrative structure.

Shirley was Commissioner of the Community and Neighbourhood Services department of the City since January of 1996.

Between 1991 and the end of 1995 she worked for the provincial government and held positions as: Assistant Deputy Minister (ADM), Ontario Women's Directorate; ADM for Social Assistance Reform, Ministry of Community and Social Services; ADM of Operations, Ministry of Housing; and CEO of the Ontario Housing Corporation.

Prior to that, Shirley worked for 11 years in Metro Toronto government in various capacities, including: Director of Policy and Planning for the Community Services department; General Manager of Administration for Exhibition Place; and Executive Director for the Metro Chairman's Office.

Shirley has a Master's Degree in Public Administration (Queen's) and a Master's Degree in Social Work (Social Policy) from the University of Toronto.