Ryukichi Inada (?? ??, Inada Ryukichi, March 18, 1874 – February 27, 1950) was a Japanese physician, a prominent academic, and bacteriologist researcher.
He was the discoverer of the Weil's disease pathogen.
In addition to his life's work in early 20th-century Japanese medical education, he was a pioneer in Japanese clinical cardiology and oncology.