Upton, previously senior director at McDonald's UK, takes up the new position to boost the company's senior leadership team in the areas of people management, operational support and supply chain.
Leon, which currently operates 35 sites in the UK, plans to grow the business to 110 sites. Last year it appointed Antony Perring chief financial officer and Chris Burford as director of finance to help with expansion.
Leon chief executive John Vincent said: “John Upton will bring more method to our magic. We want to create a company we’d be happy to pass on to our grandchildren, and John’s huge experience and strength of character are going to help us grow up big and strong.”
Upton, who spent 13 years at McDonald's UK, said: "I was personally drawn to the brand by both the delicious food and its core mission of helping everyone to eat and live well. I also really like Leon's disruptive and optimistic attitude; it innovates, bucks trends and places huge store on developing its people and helping them achieve their goals. It is a testament to this that 38 per cent of its head office team have been promoted from the kitchen floor."