A spokesman for the retailer said Robinson had been working secretly on the project for almost a year, although his role was only officially announced this week at the launch of the new service.
Robinson joined Tesco from catalogue retailer Argos, where he was financial director for four years. He also worked at Kingfisher in a number of roles - including group chief analyst and head of strategy for general merchandise - and at Superdrug as a buyer.
The spokesman added that Robinson would be based at Tesco's offices in Welwyn Garden City, Hertfordshire, and said his background with Argos made him "the ideal man".
Robinson said: "Tesco Direct will have more breadth and depth and all at the great prices our customers have come to expect."