She competed in her first Olympic games in Athens in 2004, but failed to get past the heats.
Two years later she won silver medals at 400m and 800m at the Commonwealth Games in Melbourne.
At the Beijing Games she was beaten into third place by American Katie Hoff and team-mate Rebecca Adlington, who won gold., external
But she went on to beat Adlington at the British championships the following year, setting a new world record in the process.
Jackson competed at the London 2012 Olympics in the Women’s 4x200m freestyle relay, which saw Team GB placed fifth.
“I’m now looking at new opportunities to start a Swim Academy and begin a brand new career in events,” she said.
Outgoing British Swimming national performance director Michael Scott praised Jackson’s achievements in the pool.
“To be a three-time Olympian, an Olympic, world, European and Commonwealth medallist, and to have set a world record over 400m freestyle in 2009 are all outstanding achievements,” he said.
“On behalf of all at British Swimming I would like to wish Jo all the best in her new endeavours.”
