The Ditchley Foundation is a foundation that holds conferences, with a primary focus on British-American relations. Based at Ditchley Park near Chipping Norton, Oxfordshire, it was established as a privately funded charity in 1958 by philanthropist Sir David Wills. Its current Director is James Arroyo,.

Ditchley Park is a country house near Charlbury in Oxfordshire, England. The estate was once the site of a Roman villa. Later it became a royal hunting ground, and then the property of Sir Henry Lee of Ditchley. The 2nd Earl of Lichfield built the present house, designed by James Gibbs, in 1722. In 1933, the house was bought by an MP, Ronald Tree, whose wife Nancy Lancaster redecorated it in partnership with Sibyl Colefax. During the Second World War Winston Churchill used the house as a weekend retreat, due to concerns that his official country house, Chequers and his private country home, Chartwell, were vulnerable to enemy attack. After the war, Tree sold the house and estate to the 7th Earl of Wilton, who then sold it in 1953 to Sir David Wills of the Wills tobacco family. Wills established the Ditchley Foundation for the promotion of international relations and subsequently donated the house to the governing trust.