| Name | Character | Episodes |
|---|---|---|
| David Walliams | Mr Kieth Church | 12 |
| Frances de la Tour | Ms Baron | 12 |
| Catherine Tate | Miss Sarah Postern | 12 |
| Philip Glenister | Mr Gunn | 12 |
| Steve Speirs | Mr Barber | 12 |
| Joanna Scanlan | Mrs Klebb | 10 |
| James Greene | Mr Hubble | 9 |
| Matthew Fenton | Nicholas | 9 |
| Daniel Rigby | Mr Martin | 8 |
| Jocelyn Jee Esien | Daphne | 7 |
| Julie T. Wallace | Pat | 6 |
| Joivan Wade | Manyou | 6 |
| Michele Dotrice | Rita Gunn | 1 |
| Sylvestra Le Touzel | Ms Steele | 1 |
| Morgana Robinson | Fenella Forbes | 1 |
| Tom Davis | Simon | 1 |
| Jimmy Akingbola | Dr Dalton | 1 |
| Llewella Gideon | Vicar | 1 |
| Beatrice Curnew | Other Teacher | 1 |
| Karen Taylor | Trish | 1 |
| Harmage Singh Kalirai | Photocopier Man | 1 |
| Trevor Michael Georges | Daryl | 1 |