Sir John Williams Benn, 1st Baronet, DL (13 November 1850 – 10 April 1922) was a British politician, particularly associated with London politics.
When the London County Council was established in January 1889, Benn accepted an invitation to stand as a Progressive Party candidate for East Finsbury and was elected.
Like his contemporary Will Crooks, Benn was active in the London Dock Strike of 1889, and, as an increasingly prominent local politician, was invited in 1891 to stand for Parliament as the Liberal Party candidate for St George Division of Tower Hamlets.
A year later, he returned to Parliament after winning a by-election at Devonport, a seat he retained until being defeated in 1910.
John Benn remained a member of the London County Council until his death in 1922, leading the Progressive Party until ill-health forced him to relinquish that role in 1918.