The series, written by Sarah Williams and based on the
Mary S. Lovell biography
The Mitford Girls (titled
The Sisters in the USA), is produced by Firebird Pictures. Directors for the series are Joss Agnew and Ellie Heydon with Natasha Romaniuk as series producer. The executive producers are Elizabeth Kilgarriff, Matthew Mosley and Craig Holleworth as well as Helen Perry for UKTV and Robert Schildhouse Jess O’Riordan and Stephen Nye for
BritBox. Matthew Mosley, executive producer and head of development at Firebird Pictures, is the great-grandson of Oswald Mosley—played by Joshua Sasse in the series—through his first wife
Cynthia. He described seeing Sasse in character as his great-grandfather on set for the first time as "quite surreal." First look images from filming were released in August 2024. ==Broadcast==