Ruggero Oddi (July 20, 1864 – March 22, 1913) was an Italian physiologist and anatomist who was a native of Perugia.

In 1900 he was relieved of his position at Genoa because of narcotics usage and fiscal improprieties.

While still a student, in 1887,[1] 23-year-old Oddi described a small group of circular and longitudinal muscle fibers that wrapped around the end of the bile and pancreatic ducts in 1887.

Oddi was not the original discoverer of the sphincter; English physician Francis Glisson initially identified it two centuries earlier, however it was Oddi who was first able to characterize its physiological properties.

[2] Inflammation of the junction of the duodenum and common bile duct at the sphincter of Oddi is referred to as "odditis".