MORE: JONATHAN BROWN IN PHOTOS
The Lions called a 12.30pm press conference, where Brown addressed the media along with coach Justin Leppitsch and football director Leigh Matthews.
One of the most popular players in the AFL, Brown was forced to consider his future after suffering repeated bouts of concussion – the latest against GWS in Round 13.
The 32-year-old's retirement is effective immediately, after doctors ordered Brown not to play again this year.
"It wasn't worth the risk of going out there and getting another head knock that would jeopardise my future," Brown said.
"I have come to that conclusion and I'm very content with it."
The Warrnambool product played 256 games including the Lions' three premierships in 2001-03.
"The desire to play footy was still there, but at the end of the day I think it is the right time to hang up the boots," Brown said.
“You could always play that one more game, but it only takes one instance to cause some serious damage.
"You have to consider the future and I’ve spent some time with Kylie and the kids over the past few days and that underlined for me some of the most important things in life.
"What Leppa said about ‘not owing the Club anything’ really hit home with me and definitely helped make the decision easier.
"I caught up with him last night and we talked through the decision and my future and I knew it was time and that the right decision was to retire."
JONATHAN BROWN – AT A GLANCE
DOB: 29 October 1981
AFL Games: 256
AFL Goals: 594
Recruited From: Geelong Falcons / South Warrnambool
AFL Awards
AFL Mark of the Year 2002
All Australian 2007, 2009
Coleman Medal 2007
AFLPA Best Captain 2007, 2009
AFLPA Most Courageous Player 2007, 2008, 2011
AFLPA MVP Runner-up 2007
All Australian Preliminary Squad 2008
Club Awards
Lions Premiership Player 2001, 2002, 2003
Lions Most Improved Player 2001
Lions Most Professional Player 2005, 2009
Lions Best Clubman 2005
Lions Team of the Decade Member 2006
Lions Best Forward 2007, 2008
Lions Club Champion 2007, 2008, 2009
Lions Most Courageous Player 2007, 2010
Lions Leading Goal-Kicker 2007, 2009, 2010, 2012, 2013
Lions Co-Captain 2007-2008, 2013
Lions Members Player of the Year 2009, 2010
Lions Captain 2009-2012
Lions Life Member 2009
3rd Lions Club Champion 2010
Lions Pre-Season Premiership Player 2013