| Jani Sievinen | |
| Fullname: | Jani Nikanor Sievinen |
| Strokes: | Backstroke and medley |
| Club: | Nummelan Kisaajat |
| Birth Date: | 31 March 1974 |
| Birth Place: | Vihti, Finland |
Jani Nikanor Sievinen (in Finnish pronounced as /ˈjɑni ˈsie̯ʋinen/; born 31 March 1974) is a former medley swimmer from Finland, who won the silver medal in the 200 m individual medley at the 1996 Summer Olympics in Atlanta, Georgia. In winning the World Championship 200m individual medley title in 1994, he established a new world record of 1:58.16 which lasted for almost nine years until it was broken by Michael Phelps (USA).
Jani Sievinen was married to Mari Sievinen. They have three daughters (born 2008, 2010 and 2013). Sievinen also has two sons (born 1997 and 2001) from his previous marriage to Susanna Sievinen.