Walter Willson Cobbett CBE (11 July 1847 – 22 January 1937) was an English businessman, amateur violinist and an influential patron of British chamber music from the decade before World War I until his death in 1937. He was an innovative and astute businessman with an enthusiasm for the composition and performance of chamber music. Cobbett's business successes enabled him to focus on his musical interests from about 1905.

Cobbett sponsored a series of competitions for the composition of new chamber music works by British composers and endowed the Cobbett Medal for services to chamber music. He devised and encouraged the adaption of a short musical form called a 'phantasy'. He compiled and edited the two-volume Cobbett's Cyclopedic Survey of Chamber Music, published in 1929, a comprehensive review of the musical genre.

Walter Willson Cobbett was born on 11 July 1847 at Blackheath in south-east London. His father was a businessman "of literary and musical tastes".

Young Walter was sent to France and Germany "as a supplement to his education", where he received private tuition. In about 1861, when he was aged fourteen, Cobbett received a Guadagnini violin from his father and he began studying the instrument with Joseph Dando, who introduced chamber music to his young student. Cobbett was overtaken by a "consuming enthusiasm" for the musical genre when he heard the Hungarian violinist Joseph Joachim lead a quartet performing Beethoven compositions at St. James's Hall in London. Cobbett later described the experience as akin to the opening of "an enchanted world". He wrote: "From that moment onward I became a very humble devotee of this infinitely beautiful art, and so began for me the chamber music life".

Cobbett began his business life as an underwriter employed by Lloyd's of London. He later worked in journalism, as a foreign correspondent.

By the late 1870s Cobbett had established his own business in London selling industrial goods. Cobbett was on vacation in Sweden where he met William Fenton, a Scotsman working as the weaving manager at a Swedish textile mill. Fenton had invented a sturdy twill woven belt for driving machinery, an improvement on the leather and canvas belts then being used on machines. Cobbett recognised a business opportunity and formed a partnership with Fenton to sell and market the product in Britain. In 1879 Fenton moved with his family from Sweden to Dundee in Scotland, where he established a factory to manufacture the woven belt material, the entire output of which was sold from Cobbett's offices in London. The partnership was successful and within four years both men moved to larger premises. In 1883 the manufacturing plant was transferred to Stanley in Perthshire. By the late 1880s Fenton's two sons became involved in the business, forming their own company.

Cobbett played chamber music regularly at home and was involved with several amateur orchestras including the Strolling Players' Orchestral Society, formed in about 1890.

Walter Willson Cobbett and Ada Florence Sells were married in 1889 at Lambeth in South London.