Yonekura Masaharu (米倉昌晴, May 30, 1728 – January 18, 1786) was the 3rd daimyō of Mutsuura Domain in southern Musashi Province, Honshū, Japan (modern-day Kanazawa-ku, Yokohama, Kanagawa prefecture) and 6th head of the Yonekura clan.
He was confirmed as daimyō of Mutsuura Domain in a formal audience with Shōgun Tokugawa Ieshige.
As daimyō, he was assigned to several ceremonial postings as guard of various gates to Edo Castle.
In January 1776, he became a Sōshaban (Master of Ceremonies) and in April 1777 he rose to the position of wakadoshiyori (Junior Councilor) under Shōgun Tokugawa Ieharu.
However, with the assassination of Tanuma Okitomo in April 1784, he rapidly lost favor at Court and attempted to resign his posts, but his request was refused.