The Bluebirds held off a host of competition to seal the Nigeria international's signature, and he is "very happy" to have joined the club after a rocky tenure at The Hawthorns.
The Nigerian forward had been linked with moves to Swansea and Stoke during the transfer window, but Malky Mackay's side has won the race for the 32-year-old, who has signed a two-year deal. Odemwingie becomes Cardiff's eighth signing since gaining promotion to the Premier League and will provide added firepower, having scored 30 goals in his three-year spell at The Hawthorns.
"Cardiff City Football Club is pleased to announce the signing of Peter Odemwingie from West Bromwich Albion," read a statement from the club. "Peter completed his medical on Monday afternoon and will link up with his new team-mates later this week."
Odemwingie had fallen out of favor at West Brom after he tried to force through a move to QPR in January, and he is pleased to have been given the chance to make a "fresh start" with the Premier League new boys.
"I'm delighted to complete my move to Cardiff City. I'm looking forward to this fresh start at a club that is really going places, a team that's progressing fast," Odemwingie told the club's website. "My father-in-law is a City fan and he's told me what a great club this is. I'm looking forward to meeting up with the boys and then start preparing for the trip to Hull after the international break.
"I've seen a little bit of the city, and I know that my wife and I will really enjoy living in Cardiff. I can't wait to get started - this move makes me very happy."