Caron received a qualifying offer from the Blues on Tuesday and was a restricted free agent.
The Sayabec, Quebec native played in 70 games for the Chicago Wolves last season, scoring 17 goals and 19 assists (36 points). He also played in four regular season games with the Blues.
So far this offseason, the Blues have re-signed Dmitrij Jaskin (two years), Scottie Upshall (one year) and Kyle Brodziak (two years).
Free agency opens on Friday.