Leather Lane Market
Leather Lane Market is an outdoor street market in the Holborn area of the London Borough of Camden. Taking place on Leather Lane, it is the oldest street market in Camden. Licences to trade are issued by Camden London Borough Council.

Leather Lane Market is an outdoor street market in the Holborn area of the London Borough of Camden. Taking place on Leather Lane, it is the oldest street market in Camden. Licences to trade are issued by Camden London Borough Council.
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