Sir Jeremy James Farrar is a British medical researcher who has served as Chief Scientist at the World Health Organization since 2023. He was previously the director of The Wellcome Trust from 2013 to 2023 and a professor of tropical medicine at the University of Oxford.

The Wellcome Trust is a charitable foundation focused on health research based in London, United Kingdom. It was established in 1936 with legacies from the pharmaceutical magnate Henry Wellcome to fund research to improve human and animal health. The aim of the Trust is to "support science to solve the urgent health challenges facing everyone." It had a financial endowment of £29.1 billion in 2020, making it the fourth wealthiest charitable foundation in the world. In 2012, the Wellcome Trust was described by the Financial Times as the United Kingdom's largest provider of non-governmental funding for scientific research, and one of the largest providers in the world. According to their annual report, the Wellcome Trust spent GBP £1.1 billion on charitable activities across their 2019/2020 financial year. According to the OECD, the Wellcome Trust's financing for 2019 development increased by 22% to US$327 million.