The Bundestag (Federal Diet; pronounced [ˈbʊndəstaːk]) is a constitutional and legislative body in Germany. In practice, the country is governed by a bicameral legislature, but not a bicameral parliament. While the Bundestag is sometimes viewed as the lower house and the Bundesrat the upper house both do not form a common parliament and do not have powers in the same policies. The Bundesrat generally gets involved in the federal legislative process only if the competences of the Länder (the states of Germany) are being touched by a proposed law; most laws will originate in Bundestag, but the Bundesrat may initiate and pass legislation onto the Bundestag as well. The Bundestag and the Bundesrat, like the other federal constitutional bodies, both meet in Berlin, with the Bundestag occupying the former Reichstag building.

The Bundestag was established by the German Basic Law of 1949, as the successor to the earlier Reichstag. Chapter III of the Basic Law deals entirely with the Bundestag. It meets in the Reichstag Building in Berlin. Norbert Lammert is the current President of the Bundestag. Representatives of the Bundestag are directly elected every several years, usually every four years under normal circumstances. Under some circumstances the Bundestag may be dissolved earlier (or later), such as if the Federal Chancellor loses a vote of no confidence. In such a circumstance the Chancellor may request the Federal President to hold elections and have the Bundestag dissolved earlier, insofar as the Bundestag does not vote in a new Chancellor before that. The procedures for these situations are governed by Articles 67 and 68 of the Basic Law. The Bundestag is unique in that the previously elected body continues to be able to meet and vote on matters even after its successor is chosen in an election, and until the newly elected legislature is ready to convene.