Sadahiko Miyake (三宅 貞彦, Miyake Sadahiko, 18 March 1891 – 22 October 1956) was a general in the Imperial Japanese Army, commanding Japanese ground forces on New Guinea during the closing months of the war.

In March 1939, he was promoted to colonel in the infantry and was appointed Chief of the Ordnance Section of the IJA 116th Division in 1939.

In April 1940, Miyake was appointed Commanding Officer of the IJA 80th Infantry Regiment, a garrison force in Korea.

He returned to Japan as Commanding Officer of Okayama Regimental District in April: however, in May he was ordered back to New Guinea as command of the Infantry Group of the IJA 20th Division.

Miyake was at the Battle of Finschhafen against the Australian Army between September and October 1943 during the Huon Peninsula campaign, but was forced to retreat after being defeated during the Battle of Sattelberg on 25 October 1943.