Main Cast:
* Lee Ingleby as Gerald Durrell
* Jessica Hynes as Margo Durrell
* Keeley Hawes as Louisa Durrell
* David Bradley as Larry Durrell
* Imogen Poots as Leslie Durrell
* James Fox as Dr. Theodore "Theo" Durrell
Supporting Cast:
* Patrick Malahide as S.G. Durrell
* Oliver Coleman as Gerry (young Gerald)
* Saskia Reeves as Nancy
* Rupert Graves as Douglas Burden
* Samuel West as Leslie (young Leslie)
* Ellie Kendrick as Margo (young Margo)
* Poppy Lee Friar as Leslie (young Leslie)
* David Tennant as Basil Fawlty
* Alan David as General
* Andrew Bicknell as Inspector
* Joseph Long as Roger
* George Costigan as Police Captain
* Lucy Davis as Joan
* Timothy West as Dr.
* Sheila Hancock as Aunt Mabel
* Daniel Lapaine as Michel
* John Woodvine as Professor
This list may not be exhaustive as there were many other actors in smaller roles.