Dartford is the principal town in the Borough of Dartford, Kent, England. It lies 16 miles (26 km) east south-east of central London. The town lies on the border of Kent and Greater London, bordering the London Borough of Bexley. It also borders the Borough of Thurrock, Essex, via the Dartford Crossing of the River Thames.
The town centre is in a valley through which the River Darent flows, and where the old road from London to Dover crossed: hence the name, from Darent + ford. Dartford became a market town in medieval times and, although today it is principally a commuter town for Greater London, it has a long history of religious, industrial and cultural importance. It is an important rail hub; the main through-road now avoids the town itself.
Dartford is twinned with Namyangju, South Korea.