Chelmsford 123 was a situation comedy produced for British Channel 4 television by Hat Trick Productions. It ran for two series, of six and seven episodes, in 1988 and 1990.

The series was located in the British town of Chelmsford in 123 AD and concerned the power struggle between Roman governor Aulus Paulinus (Jimmy Mulville) and the British chieftain, Badvoc (Rory McGrath). Britain is a miserable place, cold and wet, just the place to exile Aulus for accidentally insulting the Emperor's girlfriend, but also give him something useful to do. Aulus was a rather delicate Roman, who was usually outwitted by the scheming Badvoc, who hadn't had a haircut for twenty-five years. Many of the other regular "Hat Trick" actors, previously seen in e.g. Who Dares Wins, also appeared.

Principal cast

• Rory McGrath -- Badvoc, British chieftain
• Jimmy Mulville -- Aulus Paulinus, Roman Governor of Britain
• Philip Pope -- Grasientus, Aulus' assistant.
• Howard Lew Lewis -- Blagg
• Neil Pearson -- Mungo
• Erika Hoffman -- Gargamadua
• Geoffrey McGivern -- Wolfbane

 "They call me Mungo, the Evasive" "Why is that?" "Who wants to know?" 

Episode list, and first transmission dates

• Arrivaderci Roma -- 9 March 1988 (played entirely in Latin until Aulus arrives in Britain)
• What's Your Poison? -- 16 March 1988
• The Girl of My Dreams __ 23 March 1988
• One For The Road __ 30 March 1988
• Vidi Vici Veni __ 6 April 1988
• Peeled Grapes and Pedicures -- 13 April 1988
• Heads You Lose __ 9 January 1990
• Get Well Soon __ 16 January 1990
• Bird Trouble __ 23 January 1990
• Odi, et Amo __ 30 January 1990
• The Secret War __ 6 February 1990
• Mine's a Double __ 13 February 1990
• Something Beginning With 'E' __ 20 February 1990