Middlesex County

Middlesex County may refer to:

Canada

 * Middlesex County, Ontario

Jamaica

 * Middlesex County, Jamaica

United Kingdom

 * Middlesex, a historic county in England

United States

 * Middlesex County, Connecticut
 * Middlesex County, Massachusetts, the most populous Middlesex County in the United States
 * Middlesex County, New Jersey
 * Middlesex County, Virginia