The story centres on six quirky students who enter a spelling competition, and the three equally quirky adults who administer it.
Musical theatre veteran Day will play Vice Principal Panch, a senior member of the judging panel who returns to the competition after a five-year break with a fresh outlook on life thanks to his high-fibre diet and new-found love.
The subject of his unrequited affections is fellow judge and previous winner, Rona Lisa Peretti, who will be played by Niki Evans, who has starred in Blood Brothers and Legally Blonde since finding fame with ITV's X Factor.
Other cast includes: Ryhs Owen, Ellie Mason, Thomas Mackley, Janette McManus, Arina II, Ross Cobbald, Joshua Dowen, Jamie Lee Pike and Will Bradnam.
Before every performance of Spelling Bee, four audience members will be recruited through pre-show foyer interviews and audience questionnaires to participate on stage as guest spellers.
Alex Howarth, who directed a production of Spelling Bee in Edinburgh in 2012, will return for the tour alongside Lee Freeman (musical director) and Kenn Oldfield (choreographer).
The musical was conceived by Rebecca Fieldman, with music and lyrics by William Finn and additional material to Sheinkin's book by Jay Reiss. The tour is produced by ASH Productions Live and Harlow Playhouse in association with Patch of Blue Theatre Company.
It will open in Harlow (3-5 October), before going on to Croydon (8-9 October), Barnstaple (11-12 October), Birmingham (14 October), Kettering (16-17 October), Blackpool (21 October), High Wycombe (22 October), Jersey (24-26 October), Worthing (30 October), Liverpool (5-9 November), Crawley (14 November) and Eastbourne (15-16 November).
- Louise Miles