Belsham, who has been at the supermarket giant for just over two years, will join the online marketplace for small businesses in May.
Notonthehighstreet.com's co-founder and president Holly Tucker said: “We are thrilled that Simon has agreed to join us. He is an online retail and e-commerce expert and will bring great experience and energy to the role.
“Simon’s entrepreneurial background and commitment to SMEs will fit well with the ethos and ambitions we have developed at Notonthehighstreet.com.”
Belsham added: “Like many others with an interest in retail and e-commerce I have watched the company’s growing success with considerable admiration and I am looking forward to joining this dynamic and pioneering company and working closely with our community of partners.”
Notonthehighstreet.com was founded in 2006 by Tucker and Sophie Cornish, and Belsham’s appointed comes as the e-commerce company continues to grow rapidly year-on-year with 53 percent revenue increase and turnover reported at 127 million pounds in 2014.