Fonterra is a New Zealand multinational publicly traded dairy co-operative owned by around 10,500 New Zealand farmers. It was founded in 2001.

In New Zealand, as in most Western countries, dairy co-operatives have long been the main organisational structure in the industry. Back in 1871, the first dairy co-operative was established in Otago. By 1920, there were 600 dairy processing factories of which about 85% were owned by co-operatives. After World War II, with improving transportation, processing technologies and energy systems, the co-operatives merged and became larger and fewer in number. By the end of the 1990s, there were only four co-operatives nationwide: the Waikato-based New Zealand Dairy Group, the Taranaki-based Kiwi Co-operative Dairies, Westland Milk Products, and Tatua Co-operative Dairy Company. In 2001, following the merger of  New Zealand Dairy Group and Kiwi Cooperative Dairies, together with the New Zealand Dairy Board, which had been the marketing and export agent for all the co-operatives, Fonterra was established.

Fonterra effectively has monopsony control of the New Zealand domestic and export dairy industry. The merger was initially turned down by the New Zealand Commerce Commission, but later approved by the New Zealand Government, with subsequent legislation deregulating the dairy industry, allowing for the export of dairy products to be undertaken by any company. The two smaller co-operatives, Tatua and Westland, did not join Fonterra, preferring to remain independent.

Western Stars, Perfect Italiano, Bega, Australian Dairies, Mainland Cheese, Mainland Butter, Anchor, Anlene and Anmum, are some of the brands Fonterra is responsible for.

Fonterra is also New Zealand’s largest producer of biofuel, processing a waste stream from casein manufacture into bio-ethanol. The company produces around 20 million litres of premium ethanol annually.