[5] Ann McManus, the show's cocreator, devised the series in response to the BBC requesting a drama pertinent to "ordinary people in Britain today".

Series 3 introduced new deputy head Eddie Lawson (Neil Morrissey) and, in the seventh episode, new Headteacher Rachel Mason (Eva Pope).

Other staff arrivals include NQT English teacher Jasmine Koreshi (Shabana Bakhsh) and Head of Music and Drama Matt Wilding (Chris Geere).

The series features new Head of PE Rob Cleaver (Elyes Gabel), who is sacked when it transpires he is giving Bolton pills to help him win an important match.

New pupils included Emily James (Shannon Flynn) and her sister Lindsay James (Jenna-Louise Coleman), Siobhan Mailey (Phoebe Dynevor), Ros McCain (Sophie McShera), Luke Pendle (Richie Jeeves), Amy Porter (Ayesha Gwilt), Josh Stevenson (William Rush) and Finn Sharkey (Jack McMullen).

[49] Karen's family included children Jess (Linzey Cocker) and Harry (Ceallach Spellman) and her husband and supply teacher Charlie (Ian Puleston-Davies).

Lucien Laviscount was cast as rebellious teenager Jonah Kirby[50][51][52] and Chelsee Healey also reprised her role as Janeece Bryant as the new school secretary.

[55] Also introduced in episode 11 were pupils Nate Gurney (Scott Haining), Ronan Burley (Ben-Ryan Davies), Ruth Kirby (Anna Jobarteh).

Guest stars in the seventh series included: Gemma Atkinson, Dominique Jackson, Alicya Eyo, Margi Clarke, Jodie Prenger, Lisa Riley, Tupele Dorgu, Tracy-Ann Oberman, Kai Owen and Jane Asher.

[69] New pupils Kenzie Calhoun (Charlotte Beaumont),[69] Scott Fairchild (Andrew Still),[69] Carrie Norton (Tahirah Sharif), Bonnie Kincaid (Holly Jack),[69] Dale Jackson (Finlay MacMillan)[69] and Abdul Bukhari (Armin Karima),[69] alongside existing pupils Rhiannon Salt (Rebecca Craven), Lenny Brown (Joe Slater), Lisa Brown (Caitlin Gillespie), Darren Hughes (Mark Beswick), Shaznay Montrose (Je'Taime Morgan Hanley), .

[35] Staff members included Lindon King (Vincent Jerome), Joe Casey (James Baxter), Wendy Whitwell (Jo Coffey), Valerie Chambers (Shauna Shim), Neil Guthrie (Neil Fitzmaurice), Coral Walker (Rachel Leskovac), Amy Spratt (Katherine Pearce), Nicky Walters (Kym Marsh), Jamilah Omar (Sonia Ibrahim) and Mike Rutherford (Ryan Clayton).

New senior pupils included Danny Lewis (Adam Abbou), Samia Choudhry (Priyasasha Kumari), Preston Walters (Noah Valentine), Kai Sharif (Adam Ali), Kelly Jo Rafferty (Alicia Forde), Dean Weever (Francesco Piacentini-Smith), Noel McManus (Liam Scholes), and Caz Williams (Lucy Eleanor Begg).

[71][72] Series 14 introduced Jason Manford as Steve Savage, Waterloo Road's new Headteacher, and Saira Choudhry as Nisha Chandra, Head of Maths.

New students included Billy Savage (Olly Rhodes), Boz Osbourne (Nathan Wood), Aleena Qureshi (Sonya Nisa), Lois Taylor-Brown (Miya Ocego), Luca Smith (Danny Murphy), and Jared Jones (Matthew Khan).

[73][74] Series 15 introduced Lindsey Coulson as Dame Stella Drake, the new Headteacher of Waterloo Road,[75] and Lauren Patel as new early career teacher Jas Sharma.

[76] New students included Agnes Eccleston (Niamh Blackshaw),[77] Cat Guthrie (Lucy Chambers), and Ashton Stone (Cory McClane).

The podcast was hosted by cast members Adam Thomas (Donte Charles) and Priyasasha Kumari (Samia Choudhury), and released exclusively on BBC Sounds.