The Christian Democratic Union of Germany (CDU — Christlich Demokratische Union Deutschlands) is the second largest political party in Germany. A center right christian democratic party, the CDU is a member of the European People's Party (EPP) and the International Democrat Union (IDU).

The CDU does not operate in Bavaria; its role is played by the Christian Social Union (CSU). The CDU cooperates with the CSU at the federal level; although each party maintains its own structure, the two form a common caucus in the German Parliament and do not run opposing campaigns. Their combination is generally referred to as The Union.