The Jeremy and Hannelore Grantham Environmental Trust (Grantham Trust) is an organization that makes grants to environmentalist organizations with a focus on the developing world. It is a part of the Grantham Foundation for the Protection of the Environment.
The trust was founded in 2005 by Jeremy Grantham, a British investor, and his wife Hannelore. The trust supports environmentalist organizations all around the world.
The trust began being used interchangeably with the Grantham Foundation in December 2010 when it awarded the left-of-center Center for Public Integrity a $2.5 million challenge grant to focus on environmental reporting. The fund provided the grant through 5 years and was used to hire additional reporters and expand its environmental reporting. 
In December 2017, the Grantham Trust was part of a multi-organization group that awarded $20 million in grants to the Soil Health Institute, Soil Health Parternship, and the Nature Conservancy. The groups would study ways to improve the health of soil. 
In September 2018, then-California Governor Jerry Brown (D) announced plans to launch a satellite that would measure and monitor greenhouse gases and other emissions that are suspected to be responsible for climate change. The Grantham Trust announced that it would help finance the construction and launch of the satellite.  California planned to launch the satellite out of fears that the federal government under President Donald Trump would not fund research into climate change. 
Also in September 2018, the Grantham Trust joined with the William and Flora Hewlett Foundation, the IKEA Foundation, the French and German governments, and asset management firm BlackRock to form a climate finance partnership. The partnership would fund projects such as energy efficiency, renewable energy, and low carbon and electrified transportation in Latin America, Africa, and Asia. 
In March 2019, the Grantham Trust contributed $1 million to Carbon180, a nonprofit that works on carbon capture technology. It was used to fund a carbon capture plan that will capture carbon from a coal-fired power plant in Wyoming and create products that can be sold for a product. The state of Wyoming is contributing $250,000 to it. 
According to the Grantham Trust’s 2015 tax returns, it held $171 million in assets and awarded $5.8 million in grants.