Founded in 1967, Earth Trust is an environmental charity (not-for-profit organisation) which was originally known as the Northmoor Trust for Countryside Conservation. Earth Trust was initially established by the British engineer Sir Martin Wood to promote environmental conservation through land management, education, and land science. It is a registered charity under English law.

Earth Trust is the owner and manager of the largest freely accessible natural green space landscape in Oxfordshire - the iconic Wittenham Clumps: 500 hectares of woodland, farmland, wildflower meadows and wetlands. Earth Trust also care for a growing number of smaller community reserves - special places for both nature and people within urban areas and towns. These places receive 200,000+ visits each year.

As well as managing and promoting accessible natural green spaces for everyone, Earth Trust also operate a working farm. Along with their Farm Step tenants, Earth Trust are one of Oxfordshire's mid-sized producers of legumes, grains and wildflowers, beef, lamb, Goat's cheese and honey.

Earth Trust have 500 hectares of mixed use farmland, demonstrating the links between environment, wildlife, landscape and growing food. Earth Trust encourages and supports the production, distribution and eating of good quality, local, healthy food. Land management, skills and the means needed to produce and distribute food locally, minimising transport and waste are all important ingredients. Earth Trust continue to explore and develop methods to show that farming practices can be environmentally friendly and economically sustainable.

In 2009, Earth Trust came into a management position of Thrupp Lake, located in Radley.

In 2014 Earth Trust started managing Abbey Fishponds in Abingdon. Tucked away in a residential area of the town, Abbey Fishponds is a small nature reserve loved by locals and teeming with wetland wildlife. The reserve is around 7ha and despite being completely enclosed by housing, is a haven for wildlife, walkers and local explorers.

The newest Earth Trust building, Earth Lab is a cutting-edge sustainable building and winner of the “Most Innovative and Sustainable Initiative” at the 2021 OxPropFest awards. More than a building, Earth Lab is a living demonstration of human interactions with the natural environment through its design, materials and functional choices.

The ponds and backwaters were developed in 2021 and provide important habitats for people and wildlife to enjoy as well as wetlands which help to alleviate floods and absorb carbon.

Earth Trust hosts a full programme of events each year, including countryside management courses, taster workshops and family festivals. They are best known for their Lambing Weekends in spring, which were attended by over 8,000 people in 2016.