Trenton is the capital of New Jersey, a state of the United States of America. As of the United States 2000 Census, the City of Trenton had a population of 85,403. Trenton is also the county seat of Mercer County.

Trenton is located in almost the exact center of the state (the official geographic center is 5 miles (8 km) southeast of Trenton at 74° 33.5'W, 40° 4.2'N). Due to this, it is sometimes included as part of North Jersey and as the southernmost city of the New York metropolitan area. Others consider it part of South Jersey and as the northernmost city of the Delaware Valley metropolitan area. Locals consider it to be a part of Central Jersey, and thus part of neither region, though in truth the city has more communication and transportation links with the Delaware Valley than it does with New York.

Trenton is the home of the Trenton Thunder Eastern League AA minor league baseball team, which is affiliated with the New York Yankees and plays in Mercer County Waterfront Park, and the Trenton Titans (an ECHL minor league hockey affiliate of the Philadelphia Flyers) which plays in the Sovereign Bank Arena. The New Jersey State Prison, which has two maximum security units and houses the state's most dangerous criminals, is also located in Trenton.

Trenton is an anchor city for the Delaware Valley metropolitan area. Trenton and its immediate suburbs are often lumped together and referred to as "Greater Trenton" by locals.