John Mundy (or Munday) (before 1555 – 29 June 1630) was an English composer, virginalist and organist of the Renaissance period.
In 1585 he was appointed joint organist of Westminster Abbey with Nathaniel Giles, a post he maintained until his death in 1630.
He composed sacred music in English and Latin, including music for the Book of Common Prayer, and is represented in the Fitzwilliam Virginal Book by five pieces, including a magnificent set of variations on the popular song Goe from my window and a whimsical but fine miniature, Munday's Joy.
He also wrote a setting of the recusant Chidiock Tichborne's poem My prime of youth before the latter's gruesome execution in 1586 for his part in the Babington plot.
Mundy died on 29 June 1630 at Windsor, succeeded in his post there by his colleague Nathaniel Giles.