Portobello Road
Portobello Road is a street in the Notting Hill district of the Royal Borough of Kensington and Chelsea in West London. It runs almost the length of Notting Hill from South to North, roughly parallel with Ladbroke Grove. On Saturdays it is home to Portobello Road Market, one of London's notable street markets, known for its second-hand clothes, pastries and antiques. Every August since 1996, the Portobello Film Festival has been held in locations around Portobello Road and, in 2015, Portobello Radio was founded as the area's community radio station.

Portobello Road is a street in the Notting Hill district of the Royal Borough of Kensington and Chelsea in West London. It runs almost the length of Notting Hill from South to North, roughly parallel with Ladbroke Grove. On Saturdays it is home to Portobello Road Market, one of London's notable street markets, known for its second-hand clothes, pastries and antiques. Every August since 1996, the Portobello Film Festival has been held in locations around Portobello Road and, in 2015, Portobello Radio was founded as the area's community radio station.
Check the official site before travelling; hours and prices can change.
More markets

Borough Market
London's defining food market — go early Saturday, eat your way around the perimeter.

Columbia Road Flower Market
Sunday-only flower market in the East End — 8 a.m. for choice, 2 p.m. for prices.

Maltby Street Market
Borough's smaller, scruffier sibling — railway arches, weekend only.
Source: wiki-list