Teddington is a largely suburban town centred on a linear settlement in the London Borough of Richmond upon Thames in southwest London. It is located on the north bank of the River Thames, between Hampton Wick and Twickenham, 10.4 miles (16.7 km) south west of Charing Cross (a point considered to be the centre of London from which distances are measured). It stretches inland from the River Thames to Bushy Park. Prior to the creation of Greater London in 1965, Teddington was in the county of Middlesex which was abolished in the reorganization.
Teddington has the site of the first/last lock on the River Thames, Teddington Lock, (today just within the boundaryof Ham), accessible via the Teddington Lock Footbridges. This marks the upstream limit of the Tideway, a complex of three locks of which the barge lock at 218 yards (199 m) is the longest on the river.
For more information, see the EN Wikipedia article Teddington. The History section is very informative.