Sir Stuart, one of the UK’s most well-known business leaders and current chairman of online retailer Ocado, said he tried the drug while on holiday five years ago.
Speaking to The Times magazine, Sir Stuart, 64, said his first experience with smoking marijuana was on his school leaving day.
‘I smoked a joint when I was 18 on the day I left school. I was sick as a pig,’ he said.
‘I never had a joint again until I went to a friend’s house for lunch, in a foreign country, about five years ago, and we had a very nice lunch on a very hot day looking over the sparkling sea.
‘This box of cigars went round, cigarettes, and I was fumbling around, and I found this thing and said, “What’s that?” And my host said, “Shut up and smoke it”.
‘So I did, and I giggled a lot, and he gave me two to go away with, and I smoked the other one the following day, and the following one about two months later, and I have to say, it was great!