| Kai Olav Ryen | |
| Birth Date: | 10 September 1978 |
| Birth Place: | Tynset, Norway |
| Position: | Defender |
| Years3: | 2002–2013 |
| Clubs1: | Magnor |
| Clubs3: | Kongsvinger |
| Caps3: | 271 |
| Goals3: | 21 |
Kai Olav Ryen (born 10 September 1978) is a Norwegian former footballer who played as a defender.
He hails from Eidskog and played for Magnor UL and Eidskog Fotball, then joined Kongsvinger IL ahead of the 2002 season. The club played in the Second Division. In 2010, he made his debut in the Norwegian Premier League. He retired after the 2013 season.[1]