Clarkson was born in Doncaster, West Riding of Yorkshire, the son of Shirley Gabrielle Clarkson (1934–2014), a teacher, and Edward Grenville Clarkson (1932–1994), a travelling salesman. His parents, who ran a business selling tea cosies, put their son's name down in advance for private schools, with no idea how they were going to pay the fees. However, shortly before his admission, when he was 13, his parents made two Paddington Bear stuffed toys for each of their children. These proved so popular that they started selling them through the business. Because they were manufacturing and selling the bears without regard to intellectual property rights, upon his becoming aware of the bears Michael Bond took action through his solicitors. Edward Clarkson duly traveled down to London to meet Bond's lawyer. By coincidence, he met Bond in the lift, and the two struck up an immediate rapport. Consequently, Bond awarded the Clarksons the licensing of the bear rights throughout the world, with the family eventually selling to Britain's then leading toystore, Hamleys. The income from this success enabled the Clarksons to be able to pay the fees for Jeremy to attend Hill House School, Doncaster, and later Repton School.