The 33-year-old midfielder will become a free agent with immediate effect, after ending his four-year association with the Foxes.
Wellens joined City from Doncaster Rovers in July 2009 and went on to make 149 first team appearances in all competitions, scoring six times and featuring most recently in a 2-1 defeat at Derby County in March.
During the 2012/13 season, Wellens also spent a month on loan with fellow Championship side Ipswich Town, where he made seven appearances between October and November 2012.
Leicester City would like to wish Richie well in his future career.