The first flavoured crisp was Cheese & Onion. Ireland’s Tayto Company has probably the best claim to being first to launch cheese & onion into the crisp market. Joe “Spud” Murphy, founder of Tayto, set out to add flavour to crisps in 1954, launching cheese & onion soon afterwards. The flavoured crisps were an immediate success. Crisp companies worldwide sought to buy the rights to Tayto’s technique. Golden Wonder was the first to bring Cheese & Onion to the British mainland, in 1962.
First flavour: Cheese & Onion
Museum of Crisps 