Andrew Duff was educated at Sherborne School and St John's College in Cambridge.
He began his career as a City Councillor in Cambridge, from 1982 to 1990, and was Vice-President of the Liberal Democrats from 1994 to 1997.
Between July 1999 and June 2014 Duff was elected member of the European Parliament. During this period he was member of the Group of the European Liberal, Democrat and Reform Party, member of the Bureau of the Group of the European Liberal, Democrat and Reform Party, Vice-Chair of the Delegation to the EU-Turkey Joint Parliamentary Committee, member of the Committee on Constitutional Affairs and member of the Delegation to the EU-Turkey Joint Parliamentary Committee.
Between October 2008 and November 2013 Andrew Duff was president of the Union of European Federalists (UEF).