The most people performing Shakespeare on a single day is 7,104 schoolchildren as part of the Shakespeare Schools Festival all around the UK on 3 July 2005.
Children from schools all round the UK took part playing roles in many of Shakespeare's best loved plays in theatres around the country. They reckon 92 theatres hosted 368 productions. This was organised in conjunction with the BBC.
Comments below may relate to previous holders of this record.