The Frankfurt Parliament (German: Frankfurter Nationalversammlung, literally Frankfurt National Assembly) was the first freely elected parliament for all German states, including the German-populated areas of Austria-Hungary, elected on 1 May 1848 (see German federal election, 1848).

The session was held from 18 May 1848 to 31 May 1849, in the Paulskirche at Frankfurt am Main. Its existence was both part of and the result of the "March Revolution" within the states of the German Confederation.

After long and controversial debates, the assembly produced the so-called Frankfurt Constitution (Paulskirchenverfassung or St. Paul's Church Constitution, officially the Verfassung des Deutschen Reiches) which proclaimed a German Empire based on the principles of parliamentary democracy. This constitution fulfilled the main demands of the liberal and nationalist movements of the Vormärz and provided a foundation of basic rights, both of which stood in opposition to Metternich's system of Restoration. The parliament also proposed a constitutional monarchy headed by a hereditary emperor (Kaiser).

The Prussian king Frederick William IV refused to accept the office of emperor when it was offered to him on the grounds that such a constitution and such an offer were an abridgment of the rights of the princes of the individual German states. In the 20th century, however, major elements of the Frankfurt constitution became models for the Weimar Constitution of 1919 and the Basic Law for the Federal Republic of Germany of 1949.