Beachill won the last of his three British titles in 2005
Lee Beachill will quit squash after the National Championships, which begin in Manchester on Tuesday.
The three-time national champion has been unable to return to fitness after two operations to repair knee cartilage damage last year.
"Having set myself such high standards it's difficult to justify falling short after many years of success," said Beachill, who has won nine tour titles.
Beachill became the first English-born world number one in October 2004.
The 31-year-old won successive gold medals at the Commonwealth Games in 2002 and Melbourne in 2006, as well as helping England to consecutive world team championships in 2005 and 2007.
Beachill has reached six of the last seven national finals, winning three of them, and believes the tournament would be a fitting venue to bid farewell to the sport.
"It is with great sadness that I have to announce my retirement at a stage in my career where I felt I still had so much to offer," he said.
"I feel over the past 13 years that I have had to overcome some pretty big hurdles but the knee injury I sustained last summer has proved one too many."