The contract extension comes as a reward for an impressive finish to 2008, where Lyon took the Saints to a preliminary final finish.
St Kilda CEO Archie Fraser said Lyon had impressed all at the club since taking over from Grant Thomas at the end of 2006.
“Ross is an outstanding fit and a valuable asset to our club, he works tirelessly with the list to get the absolute best out of our playing group,” Lyon said.
“Everyone at the club and the Board has a high level of confidence in Ross to lead the club throughout the next few years.”
Lyon has a 53 per cent winning record as a coach, with 25 wins, one draw and 22 losses in two seasons at the helm.
The 42-year-old said he was excited to enter the next phase of his coaching career.
“I’m really looking forward to the next few years at the Saints. The club understands that we have a challenge ahead of us to bridge the gap to the competition leaders but we are in the process of building our list to a point where we have the confidence that we can compete with the best,” Lyon said.
“I feel extremely privileged to be coaching at St Kilda. The club is about to enter a very exciting period and I will be doing everything that I can to repay the faith shown in me by the football club and also our supporters.”
