Cheddar cheese, commonly known as cheddar, is a relatively hard, off-white (or orange if colourings such as annatto are added), sometimes sharp-tasting, natural cheese. Originating in the English village of Cheddar in Somerset, cheeses of this style are now produced all over the world.

Cheddar is the most popular type of cheese in the UK, accounting for 51% of the country's £1.9 billion annual cheese market. It is the second-most popular cheese in the US behind mozzarella, with an average annual consumption of 10 lb (4.5 kg) per capita. The US produced approximately 3,000,000,000 lb (1,300,000 long tons; 1,400,000 tonnes) of cheddar cheese in 2014, and the UK produced 258,000 long tons (262,000 tonnes) in 2008.