Initially a grammar school for boys, WGS was founded in 1512 by Sir Stephen Jenyns, a master of the ancient guild of Merchant Taylors, who was also Lord Mayor of London in the year of Henry VIII's coronation.

In September 1984, after 472 years as an all-boys school, the school admitted girls to the sixth form and in other embraces of modernity was the largest single user of assisted places funds, with over 40% of pupils in the 1980s and early 1990s reliant upon assisted places funding.

This included construction of a rock climbing wall, which replaced an Eton Fives court behind the sports centre.

A new large extension to the music block was also completed in 2005, and officially opened by Robert Plant.

In December 2007, a new block for the arts was opened on Merridale Lane, beyond Moreton's Piece, with a production of As You Like It and an exhibition by artist in residence Derek Jones.