Towcester, the Roman town of Lactodorum, is an affluent market town in south Northamptonshire, England.
The town is about 9 miles (14.5 km) southwest of Northampton and about 11 miles (17.7 km) northwest of Milton Keynes, the nearest main towns.
The name comes from the Latin for "Camp on the (river) Tove".
Towcester is famous for its racecourse. Many important national horse racing events are held there. Greyhound racing is also held at the same venue. In 2010 the World Hovercraft Championship was held on the racecourse.
Nearby is the Silverstone motor racing circuit, currently home to the British Grand Prix. In fiction the "Saracen's Head Inn" in Towcester features in Charles Dickens's novel The Pickwick Papers as one of Mr Pickwick's stopping places along what is now the A5 trunk road.