Colless, who joined the Swans' board in 1993 and took over as chairman the following season, has decided the time is right to hand over to someone else after overseeing a complete transformation of the once battling club.
"There is no particular reason for this decision other than the old adage that it is probably about time,’’ Colless said.
“I want to place on record how indebted I am for the support of the hundreds, but probably thousands of people, over the last 20 years. It has been truly remarkable.
“This support has ranged from my wife and children, to board colleagues, senior management staff including volunteers, coaches, players, support staff, sponsors, members, supporters, the AFL, media, stadium managers and numerous other categories.
“It has been one of the great privileges of my life to be associated with this extraordinary organisation."
Richard Colless with the 2012 premiership cup. Picture: AFL Media
Colless has battled health problems in recent years, including a struggle with depression in 2009 and 2010 he felt could be associated with head knocks from his playing days in Western Australia.
At the conclusion of the 1993 season, the Swans were a one-win laughing stock, but within three years a side led by Tony Lockett, Paul Kelly and Paul Roos lost a Grand Final to North Melbourne.
Since then the Swans have missed the finals on just three occasions and have developed a culture that is lauded across the country and used as a model by a range of sporting codes.
The club defeated West Coast in the epic 2005 Grand Final, ending a 72-year premiership drought, the longest in Australian football history.
Another flag followed last season and the club has since set an all-time membership record after surging past 33,000 members earlier this year.
Colless celebrates after the 2012 Grand Final. Picture: AFL Media
Chief executive Andrew Ireland, who described Colless as "one of the greatest people to ever be involved in the club" earlier this year, again paid tribute to the outgoing chairman on Thursday.
“Richard’s contribution to the club, spanning 20 years, has been quite remarkable,” Ireland said.
“He has shown a unique ability to understand how a membership-based club playing in Australia’s premier sporting competition, in the nation’s most competitive sporting market, best operates.
“Above all else, he has an unwavering passion for the club, the game and its history."
A long-serving player and coach in the West Australian Amateur Football League, Colless could make a smooth transition into management, appointed to the WAFL board in 1984 and helping drive West Coast's entry to the AFL.
A successful figure in the financial services industry for over 25 years, Colless became a member of the Order of Australia in 2006 for his services to Australian rules football.
A life member of the AFL, he undoubtedly views his time at the Swans as his greatest achievement.
“I think Bobby Skilton recently said that for most of his life the club was looked down on and now it’s a role model," Colless said at this year's guernsey presentation.
"And that is very reassuring."
James Dampney is a reporter for AFL.com.au. Follow him on Twitter: @AFL_JD.
