Izzard will play Scottish radar inventor Robert Watson-Watt, and Laura Fraser ("Breaking Bad") will play his wife Margaret.
Directed by Gillies MacKinnon, the cast also includes Alex Jennings ("The Queen"), Tim McInnerny ("The Devil’s Whore"), David Hayman ("Trial And Retribution") and Julian Rhind-Tutt.
"Castles In The Sky" will tell the story of the fight behind the invention of radar, which saved the country in the Battle of Britain during WWII.
Izzard told the Hollywood Reporter, "I feel very privileged to be playing the role of Robert Watson-Watt. Hopefully our production will allow him, along with Arnold 'Skip' Wilkins and their team, to finally take their places in the pantheon of British greats of World War II."
The show, which will feature a script by Ian Kershaw ("Shameless"), is produced by Simon Wheeler for Hero Film and Television with Arabella Page Croft and Kieran Parker co-producing for Black Camel Pictures. Izzard's stage credits include A Day in the Death of Joe Egg and Race. The two-time Emmy winner has starred in "Eddie Izzard: Dress to Kill," "The Riches," "United States of Tara" and "Across the Universe."