Gary Titley received a bachelor's degree in history and pedagogy in 1971. Two years later he obtained a teacher’s degree. Titley joined the Labour Party, and from 1981 to 1986, he was involved in local government activities.
In 1989 Gary Titley was elected member of the European Parliament and remained an MEP until 2009. During that time he was member of the Socialist Group, member of the Group of the Party of European Socialists, member of the Socialist Group in the European Parliament, Chair of the Delegation for relations with Finland, Chair of the Delegation to the EC-Finland Joint Parliamentary Committee, Chair of the Delegation to the EC-European Economic Area Joint Parliamentary Committee, Chair of the Delegation to the EU-Lithuania Joint Parliamentary Committee, Chair of the Conference of Delegation Chairs, Vice-Chair of the Delegation for relations with the Czech Republic, the Slovak Republic and Slovenia, Vice-Chair of the Delegation to the European Economic Area Joint Parliamentary Committee (EEA), Vice-Chair of the Delegation to the EU-Czech Republic Joint Parliamentary Committee, Vice-Chair of the Delegation for relations with Slovenia, Vice-Chair of the Delegation to the EU-Slovenia Joint Parliamentary Committee, Vice-Chair of the Delegation to the EU-Croatia Joint Parliamentary Committee, member of the Committee on External Economic Relations, member of the Delegation for relations with the countries of South America, member of the Committee on Foreign Affairs and Security, member of the Delegation for relations with Finland, member of the Delegation to the EC-Finland Joint Parliamentary Committee, member of the Subcommittee on Human Rights, member of the Committee on Foreign Affairs, Security and Defence Policy, member of the Subcommittee on Security and Disarmament, member of the Delegation to the European Economic Area Joint Parliamentary Committee (EEA), member of the Delegation to the EU-Czech Republic Joint Parliamentary Committee, member of the Delegation for relations with Slovenia, member of the Committee on Foreign Affairs, Human Rights, Common Security and Defence Policy, member of the Conference of Delegation Chairs, member of the Committee on Industry, External Trade, Research and Energy, member of the Delegation to the EU-Lithuania Joint Parliamentary Committee, member o fthe Committee on Transport and Tourism, member of the Committee on Transport and Tourism, member of the Committee on Legal Affairs and member of the Committee on Budgets.