Lock & Co. Hatters (formally James Lock and Company Limited) is the world's oldest hat shop, the world's 34th oldest family-owned business and is a Royal warrant holder. Its shop is located at 6 St James's Street, London and is a Grade II* listed building.

The company was founded in 1676 by Robert Davis. His son Charles continued the business and took James Lock (1731–1806) on as an apprentice in 1747. James later married Charles Davis's only child, Mary. When Davis died in 1759, James Lock inherited the company from his former master, and the Lock family, James's descendants, still own and run the company today. The shop has been in its current location since 1765.

The company is responsible for the origination of the bowler hat. In 1849, Edward Coke, nephew of Thomas Coke, 1st Earl of Leicester and the younger brother of Thomas Coke, 2nd Earl of Leicester, requested a hat to solve the problem of gamekeepers' headgear.  Traditional top hats were too fragile and too tall (often getting knocked off by low branches) for the job.

The company commissioned London hat-makers William and Thomas Bowler to solve the problem.  Lock & Co. is a Royal warrant holder as Hatter to Prince Philip, Duke of Edinburgh and Charles, Prince of Wales.

According to en.wikipedia