Under Aylwin's leadership, Booker Direct, which delivers direct to Booker's larger customers from three distribution centres in Hatfield, Livingstone and Haydock, has grown to more than £70m sales a year.
"Mark has done a great job developing our direct business and I'm delighted that he is now joining the group board," said Booker chairman Richard Rose.
Aylwin was formerly CEO of online wholesaler Blueheath and was retained by Booker when it bought Blueheath in 2007.
Aylwin, who has 357,000 shares in Booker, was previously supply chain and IT director at Musgrave GB, which owns the Budgens and Londis fascias. He was also commercial director for non-foods and supply chain director at Safeway.