The 1001: A Nature Trust, the contributors to which are sometimes referred to as the 1001 Club, is a financial endowment that helps fund the World Wide Fund for Nature. It was established in 1970 by the then-head of the WWF, Prince Bernhard of the Netherlands, with help from Anton Rupert, a South African entrepreneur.

The World Wide Fund for Nature (WWF) is a Swiss-based international non-governmental organization founded in 1961 that works in the field of wilderness preservation and the reduction of human impact on the environment. It was formerly named the World Wildlife Fund, which remains its official name in Canada and the United States. WWF is the world's largest conservation organization, with over five million supporters worldwide, working in more than 100 countries and supporting around 3,000 conservation and environmental projects. They have invested over $1 billion in more than 12,000 conservation initiatives since 1995. WWF is a foundation with 65% of funding from individuals and bequests, 17% from government sources and 8% from corporations in 2020.