The poster has been created by HHCL/Red Cell and warns people "If you don't get Sky you don't get Jack", a reference to the main character Agent Jack Bauer, played by Kiefer Sutherland.
Sky is backing the poster campaign with a national press and magazine advertising campaign to appear prior to the launch of the programme on Sky One in February.
Sky won the rights to the hit US drama after the BBC said Fox was asking for too much cash for the third series, which has attacted a smaller audience in the US.
The first two series, set in Los Angeles at the FBI anti-terrorist squad CTU, were screened on BBC Two and BBC Three on Sunday evenings. Sky is reported to have paid as much as £10m for the rights.
Barnaby Dawe, head of marketing communications at Sky TV, said: "This is a neat way of communicating to loyal '24' viewers that the show is now only available to watch on Sky One. The second wave of the campaign will aim to bring new viewers to the show."
The ad was created by Billy Faithful and Ross Neil of HHCL/Red Cell. Media planning and buying is through Universal McCann.
'24' has won a cult following, intriguing viewers with its outlandish plots and real-time action, where each episode recounts the events of one hour while the entire series takes place over the course of the day. The third series deals with a biological terrorism attack.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .