The three-year contract, which industry sources estimate could be worth £25m, begins at the start of the 2006/07 season. It follows the struggling electronics firm's deal with FIFA to become an official World Cup sponsor after next year's tournament in Germany.
The UEFA deal gives Sony exclusivity in the electronics and mobile phone categories, providing major exposure for itself and its Sony Ericsson brand, both within stadia and on live broadcasts.
The tie-up, which is being viewed as a crucial element of Sony's revival strategy, will not affect PlayStation's existing deal with the Champions League. The video-games console is believed to be finalising a renewal deal for the next contract period.
UEFA has revamped its sponsorship structure for the 2006-2009 period, boosting the number of top-tier partners from four to six.
Sony is the second brand to sign up to the overhauled contracts. Heineken announced in May it was to take over the sponsorship deal of sister brand Amstel.