David Fraser Charnley (10 October 1935 – 3 March 2012) was born in Dartford. He was a lightweight boxer, considered to be one of the greatest British fighters in his weight class. Known as "The Dartford Destroyer", Charnley had a 10-year professional career lasting from 1954 to 1964. There is information about his life on Wikipedia https://en.wikipedia.org/wiki/Dave_Charnley.
The plaque shown below was recently attached to the Scout Hall in Little Queen Street, Dartford.