The pair will star in BBC One's Woody which is set on a fictional Spanish island and features Novak as the title character - an undercover reporter forced to flee the UK after he is set up by his corrupt editor.
Walsh plays his former mentor who runs a bar on the island and puts Woody to work on a series of investigations into local life which require him to adopt different disguises.
BBC comedy boss Shane Allen, who helped discover Novak while working at Channel 4, said: "Woody is a really ambitious, colourful, feel-good comedy with two lovable rogues at the heart of it in Kayvan and Bradley.
"They'll bring sunshine and laughs to BBC One."
The show's producer Ben Palmer said it was "a silly big-hearted piece of escapism".
Novak, who got his big break playing dozens of different characters in the prank call show on Channel 4, joked: "Woody is the part I have dreamed of playing since I was a kid.
"That and Boba Fett. "