Openfield is a British grain marketing and arable inputs co-operative based in Lincolnshire. It is one of Britain's largest agricultural companies and Britain's only national co-operative in its field, with a turnover of over £550m. It markets grain for farmers and grain stores. In other countries, mainly Canada, this type of company is known as a wheat pool. The head office is based on the former RAF North Witham and prominent customers include some of the largest and well known British food and drink brands in the UK.