Friedrich Trendelenburg (24 May 1844 – 15 December 1924) was a German surgeon. He was son of the philosopher Friedrich Adolf Trendelenburg, father of the pharmacologist Paul Trendelenburg and grandfather of the pharmacologist Ullrich Georg Trendelenburg.
Trendelenburg was born in Berlin and studied medicine at the University of Glasgow and the University of Edinburgh. He completed his studies at the Charité - Universitätsmedizin Berlin under Bernhard von Langenbeck, receiving his doctorate in 1866. He practiced medicine at the and the University of Bonn. In 1895 he became surgeon-in-chief at the University of Leipzig.
Trendelenburg was interested in the history of surgery. He founded the German Surgical Society in 1872. Trendelenburg was also interested in the surgical removal of pulmonary emboli. His student, Martin Kirschner, performed the first successful pulmonary embolectomy in 1924, shortly before Trendelenburg's death. He died in 1924 of cancer of the mandible, aged 80.
A number of medical treatments and terminologies have been named after Friedrich Trendelenburg, including: