Franz Tunder (1614–1667) was a German composer and organist of the early to middle Baroque era. He was an important link between the early German Baroque style which was based on Venetian models, and the later Baroque style which culminated in the music of Johann Sebastian Bach; in addition he was formative in the development of the chorale cantata.

According to recent research, Tunder was born in Lübeck, not in Bannesdorf or Burg on the island of Fehmarn as was believed by earlier scholars. Little is known about his early life other than that his talent was sufficient to allow him to be appointed as court organist to Frederick III, Duke of Holstein-Gottorp in Gottorf at the age of eighteen. A few years earlier, he had gone to Italy in the company of Johann Heckelauer, and it is likely that he studied with Girolamo Frescobaldi while he was in Florence.

Between 1632 and 1641, Tunder worked in Gottorf as "Hoforganist". In 1641 he was appointed as the main organist at Lübeck's main church, the Marienkirche, succeeding Peter Hasse; in 1647 he became administrator and treasurer there as well. He held that post for the rest of his life; his successor was Dieterich Buxtehude, who married Tunder's daughter Anna Margarethe in 1668.

Tunder began the tradition of "Abendmusiken", a long series of free concerts in the Marienkirche, the most elaborate of which were before Christmas time. The earliest of these concerts was given in 1646. The concerts seem to have originated as organ performances specifically for the businessmen who congregated at the weekly opening of the town's stock exchange. These concerts continued through the seventeenth and seventeenth centuries; they were distinguished from other concerts by having free admission (for they took place in a church), and by being financed by the business community.