LEO I

1951 — J. Lyons & Co., London

LEO (Lyons Electronic Office) was the world's first computer used for commercial business applications. It was built by J. Lyons and Co., a British catering and food manufacturing company best known for its tea shops.

On November 29, 1951, LEO ran its first business application: Bakery Valuations. It calculated the daily value of bakery output, optimized delivery routes, and generated invoices — tasks that had previously required a team of clerks working all day.

LEO proved that computers were not just for science and military — they could transform everyday business. A tea company showed the world the future of computing.