A new adaptation of The Worst Witch was in development with the BBC starting in 2014, and Jill Murphy, author of the original book series, said she hoped the new series would be "wonderful".

Bella Ramsey, previously known for Game of Thrones, was cast as Mildred Hubble and noted she drew personal similarities with the character.

Bella Ramsey left the show before the fourth series for mental and physical health reasons, with Lydia Page taking over the role of Mildred.

The role of Maud Spellbody was recast between seasons: Meibh Campbell played her in series 1 before being replaced by Megan Hughes from series 2 onward, who had to go through two auditions to land the part.

Tamara Smart auditioned for four months before being cast as Enid Nightshade, describing the process as long and nerve-racking but exciting.

Tallulah Milligan, who plays Drusilla Paddock, is the daughter of actress Angela Griffin, known for Coronation Street and Waterloo Road.

The series was filmed at real castle locations including Peckforton Castle in Cheshire, England, and Burg Hohenzollern in the Swabian Alps, Germany.

For its second series, filming also took place at Adlington Hall in Cheshire, using its grand hall, minstrel's gallery, and surrounding countryside and woods as backdrops.

Bella Ramsey described filming as generally good but found learning the stunts challenging.