Northfield is a village in Cook County, Illinois, United States, located approximately 19 miles (31 km) north of downtown Chicago.

According to the 2021 census gazetteer files, Northfield has a total area of 3.23 square miles (8.37 km2), all land.

Northfield is home to New Trier High School's freshman campus.

A small part of Northfield (east of the former Chicago and Northwestern train tracks) is served by Avoca School District 37 in Wilmette.

Christian Heritage Academy is a private school in Northfield that serves students in preschool through twelfth grade.

The local Catholic parish, St. Phillip the Apostle, ran an elementary school which closed in 2004.

The Northfield Fire Rescue Department's Paramedic program is overseen by Saint Francis Hospital in Evanston, as part of Illinois EMS Region X.

The police department, operated out of one station within the city hall complex, is well known for professionalism and good community relations.

The Stepan Company, a manufacturer of specialty chemicals, is also headquartered in Northfield.