Rear Admiral Royal Rodney Ingersoll (4 December 1847 – 21 April 1931) was a United States Navy officer whose career extended from the late 1860s through World War I. Ingersoll was born in Niles, Michigan on 4 December 1847 and graduated from the United States Naval Academy in 1868.

He taught and wrote about ordnance subjects during several tours at the Academy, and in the early years of the 20th century commanded such ships as Bennington (PG-4), New Orleans (CL-22), and Maryland (ACR-8).

Rear Admiral Ingersoll retired in 1909, but was recalled up to duty during World War I as President of the Naval Ordnance Board.

In 1919 he returned to his home in La Porte, Indiana, where he was active in public affairs until his death on 21 April 1931 at age 83.

His son, Admiral Royal Eason Ingersoll (1883–1976), commanded the US Atlantic Fleet during World War II.