The International Democracy Union (IDU; known as the International Democrat Union until September 2023) is an international alliance of centre-right to right-wing political parties. Headquartered in Munich, Germany, the IDU consists of 84 full and associate members from 65 countries. It is chaired by Stephen Harper, former prime minister of Canada. It has three affiliated international organizations (International Young Democrat Union, International Women's Democracy Union and SME Global) and six affiliated regional organizations (Union of Latin American Parties, Asia Pacific Democrat Union, Caribbean Democrat Union, Democrat Union of Africa, European People's Party and European Conservatives and Reformists Party).
The IDU allows "centre-right" conservative political parties around the world to establish contacts and discuss different views on public policy and related matters. Their stated goal is the promotion of "democracy and [of] centre-right policies around the globe". The IDU has some overlap of member parties with the Centrist Democrat International (CDI), but the CDI is more centrist, Christian democrat and communitarian than the IDU.