Medford is a city 6.7 miles northwest of downtown Boston on the Mystic River in Middlesex County, Massachusetts, United States. At the tim…Medford is a city 6.7 miles northwest of downtown Boston on the Mystic River in Middlesex County, Massachusetts, United States. At the time of the 2020 U.S. Census, Medford's population was 59,659. It is home to Tufts University, which has its campus on both sides of the Medford and Somerville border.