15] 1894) was a Baltic German physiologist and anatomist from what was then the Governorate of Livonia in the Russian Empire.

In 1834 he received his doctorate from the University of Dorpat, where he became a professor of anatomy (1842), and physiology and pathology (1843).

Bidder is primarily remembered for his studies of nutrition and gastric physiology.

From 1847 to 1852 he performed physiological-chemical studies of digestive juices and metabolism with chemist Carl Ernst Heinrich Schmidt (1822–1894).

He also conducted important investigations of the sympathetic nervous system with Alfred Wilhelm Volkmann (1801–1877) and of the spinal cord with Karl Wilhelm von Kupffer (1829–1902).