The Capital Ring is a strategic circular walking route in London, around 125 km (78 mi) in length. It is promoted by London's 33 local councils, led by the City of London Corporation in partnership with the Greater London Authority and its functional body for regional transport, Transport for London, through which much of the funding is provided. It is called a "ring" because the route completely encircles inner and central London. The official start of the route is the Woolwich foot tunnel, but the nature of the route means that it can be started or finished at any point. The route signs feature a logo showing Big Ben in a ring of arrows.

The idea originated in 1990 at one of the early meetings of the London Walking Forum, and the route was completed in September 2005. It passes through green areas of urban and suburban London.

Some Capital Ring sections start and/or end at public transport stops. However, most sections involve a further signposted 'Capital Ring Link' to the nearest railway or underground station. Additionally, there are waymarked 'Capital Ring Links' to stations midway along some sections.

Here the Capital Ring comprises three walks, 1 to 3. These are part of the South East London Green Chain. It starts from the Woolwich foot tunnel and ends in Crystal Palace Park. Points of interest in this section include the Thames Barrier, Severndroog Castle, Eltham Palace and the remains of The Crystal Palace.

In this section, the trail comprises two walks, walk 4 and 5. Points of interest in this section include Biggin Wood (one of the few remnants of the Great North Wood), Streatham Common, Tooting Bec Lido and Wandsworth Common. The part around Balham and Earlsfield is the nearest part of the ring to central London (about 4.5 miles from Charing Cross).

Here the Capital Ring comprises two walks, walk 6 and 7. Walk 6 consists of a brief walk through suburban Wimbledon Park, then crosses Wimbledon Common, intersects the Beverley Brook Walk and then crosses Richmond Park. While the route passes within about 100 metres of King Henry VIII's Mound, with its protected view of St Paul's Cathedral, this is not indicated on the signposts for the route. Walk 7 continues from Richmond along the Thames, before deviating through old Isleworth, then through the grounds of Syon Park. It then continues along the Grand Union Canal to Osterley Lock.

Here the Capital Ring comprises two walks, walk 8 and 9. Points of interest in this section include the River Brent, the Wharncliffe Viaduct, Horsenden Hill (with panoramic views) and Harrow School. The Capital Ring's most distant part from central London is in Harrow (about 10 miles from Charing Cross).

The Capital Ring comprises two walks, walk 10 and 11, in North London.