Mōri Katsunaga (毛利 勝永, 1577 – June 4, 1615) was an officer for the Toyotomi clan following the 16th-century Azuchi-Momoyama period through the early years of the 17th-century Edo period in Japan.
Katsunaga fought in the Battle of Sekigahara and at the western legion but was met with defeat there. Later, during the Siege of Osaka, Katsunaga tricked a guard to infiltrate Osaka castle. He defeated Honda Tadatomo (an officer for the Tokugawa) there in the summer.