The CDU Baden-Württemberg (CDU BW or CDU BaWü) is the political party with the most members in the German state of Baden-Württemberg and the second largest state party (in German, Landespartei or Landesverband) of the Christian Democratic Union of Germany with almost 65,000 members. Its chairman is Thomas Strobl, who succeeded Stefan Mappus after the lost 2011 election.

Its predecessors were the Badische Christlich-Soziale Volkspartei (BCSV), the Christlich-demokratische Partei (CDP), and the Christlich-Soziale Volkspartei.

The state party was founded in January 1971, when the state parties of CDU Nordbaden, Südbaden, Nordwürttemberg, and Württemberg-Hohenzollern merged into a single party. The first chairman was Hans Filbinger.

The CDU has been the governing party of Baden-Württemberg continuously from 1953 to 2011, the year Winfried Kretschmann of the Alliance '90/Greens won the regional state elections. ^{[citation needed]}

The CDU Baden-Württemberg won absolute majorities in the 5 state elections between 1972 and 1988, and could govern the state alone. Otherwise the party cooperated with other parties. Until 1958, it cooperated with all parties represented in the parliament. The SPD withdrew from the cooperation in 1958. From 1964 CDU cooperated with FDP/DVP. In the elections of 1968, the SPD won 29% and the NPD won 10%. A grand coalition of CDU and SPD lasted from 1968 to 1972. A new grand coalition lasted from 1992 to 1996. Since 1996, the CDU is cooperating with the FDP.