Big School is co-written by Walliams and centres around a dysfunctional staff room and the unrequited love of Walliams's chemistry teacher Mr Church and Tate's French teacher Miss Postem.
Mr Church is just about to quit the school, but stops himself from handing in his notice after falling in love at first sight with Miss Postem.
The show's ensemble cast includes Life on Mars star Philip Glenister as lothario gym teacher Mr Gunn, Frances de la Tour as no-nonsense headmistress Ms Baron and The Thick of It actress Joanna Scanlan as drama teacher Mrs Klebb.
Daniel Rigby (Eric and Ernie) and Steve Speirs (Cemetery Junction) will also star.
BBC Comedy's Mark Freeland said that it had been an "absolute privilege" working with Walliams and the cast.