The former Middlesbrough defender, 30, becomes the latest player to join the Bluebirds after the summer arrivals of Craig Bellamy, Seyi Olofinjana, Jason Koumas and others.
Riggott has suffered with injuries hance the lengthy medicals at Cardiff but Dave Jones will be hoping he can make a telling contribution in South Wales.
Riggott started just 95 league games for 'boro in seven years at The Riverside. He did have a spell on loan at Stoke where he played 9 games. He started his career at Derby County who sold him to Middlesbrough for £2m in 2003.
We wish him all the best and an injury free time with at the CCS.