The 29-year-old Vancouver resident spent 10 years with the national team. He retires as the Canadian record-holder in both the 50- and 100-metre breaststroke in the long-course pool.
"I'm going to miss my teammates the most," Dickens said in a release. "I was very proud to represent the greatest country in the world for so many years and at such big events as the Olympic Games. It was a gradual decision to stop but I'm at peace with it now."
Dickens made his first Olympic appearance at the Athens Games in 2004 but didn't make the cut for the squad that went to the Beijing Olympics four years later. It was the turning point in his career as he roared back with four solid seasons capped by an appearance at the 2012 Olympics in London.
Dickens clocked his national record time of 59.85 seconds in the 100-metre breaststroke at the Games.
"I wasn't ready to retire in 2008, I couldn't do it," he said. "I wanted to be at the pool and I wanted to train. There was nothing I loved more than testing the limits of the human body. There was a challenge every day."
Dickens also competed at two Commonwealth Games, two Pan Am Games and three FINA world championships.