Although not considered a spin-off by the BBC or writer-creators Galton and Simpson, Sid James's character in Citizen James was in just about every way identical to the character he had played in Hancock's Half Hour on both radio and television.

Citizen James was created as a vehicle for Sid James after Tony Hancock opted to go solo for what would prove to be the final series of his hit sitcom Hancock's Half Hour, which was retitled Hancock for its final run. Sid had starred alongside Tony for six series and the public had come to view them as somewhat of a double-act, despite Sid's hugely successful film career alone.

Ray Galton and Alan Simpson began writing Citizen James in an office at Elstree Studios, whilst filming The Rebel with Tony Hancock.