English sanitary engineer Marshall P. Knutt is mistaken for a lawman when Judge Burke sends for help to rid Stodge City of the Rumpo Kid and his gang of desperadoes.
Following the success of Carry On Cleo (1963), Talbot Rothwell began work on another movie pastiche, while director Gerald Thomas, producer Peter Rogers and regulars Sid James, Joan Sims and Jim Dale took a busman's holiday on the sub-Ealing crime caper, The Big Job. This nine-month hiatus gave Rothwell the leisure to produce a polished screenplay whose lampoons demonstrated an obvious knowledge of and affection for the Western. Indeed, over the series as a whole, only its immediate successor, Carry On Screaming revealed a surer sense of genre.
Cowboy is easily the franchise's darkest hour. Gone is the cartoonish socko of Cleo and in its place comes real violence, with the Rumpo Kid blithely gunning down those who stand in his path, while Annie Oakley (Angela Douglas) harbours tangible hatred in her determination to avenge her father's murder. Consequently, the standard of the acting is higher than usual, with the cast maintaining credible American accents throughout (although Charles Hawtrey and the debuting Bernard Bresslaw respectively resort to patronising parody as Big and Little Heap). Indeed, Sid and his fellow outlaws even learned to ride - although they had to be content with galloping across Chobham Common in Surrey rather than the wild frontier. Black Park (a favourite Hammer location) stood in for the Reservation, while the Stodge City set at Pinewood had to be constructed with a right turn at the end of the main street to disguise the fact that a motorway and some studio outbuildings lay behind it rather than the open plains. Although they had been primarily associated with comedy since they'd first teamed on radio's Hancock's Half Hour, James and Williams were respected character actors and they clearly responded to the film's challenges, as did Joan Sims, who gives one of her best performances as the glamorous Belle.
Definitely one of the more accomplished genre spoofs in the series although lacking some of the classic raw comic moments of the more renowned of the franchise.