The activity, which runs until 6 April, is split into three parts - station advertising near the Ideal Home Show currently running at Earls Court, plus sponsorship of the London Underground map and Oyster ticket wallets.
Ikea advertising will dominate CBS Outdoor's media at Earl's Court Tube station, targeting passengers with standard and digital formats.
Ikea will also sponsor London Underground maps, including 1,672 wall-mounted maps at Tube stations and six million handheld maps, until March 2009. Additionally, the Ikea logo will appear on four million Oyster card wallets, branded inside with the message: "Travel is a means to an end. Home."
CBS already handles the ad sales contract for the London Underground, worth £1.5bn. It is rolling out a range of new formats as part of a £72m investment that will include the launch of cross-track projection and digital screens.