Midfielder Adam Miller is one of eight players to be released by new Gillingham manager Andy Hessenthaler.
The 28-year-old was brought to the Kent club from Stevenage in 2008 by former manager Mark Stimson, who was sacked after the Gills were relegated to League Two at the end of the season.
Miller made 97 appearances during his time at the Gills, scoring 13 times, including crucial goals against Leeds United, MK Dons and Brighton as the Kent side tried to beat the drop.
Hessenthaler has also released Tom Wynter, Rashid Yussuff, Stewart Lewis, Luis Cumbers, Andy Pugh, James Walker and Jacob Erskine.
Former Watford star Hessenthaler, who arrived at Priestfield from Dover Athletic last week, is in his second stint as Gills boss after managing the club from 2000-04.