Kasi Maru or Kashi Maru (橿丸, Kashi Maru, "live oak") was a Japanese auxiliary minelayer/merchant ship, sunk in Mbaeroko Bay, near Munda, during a World War II bombing raid on 2 July 1943.

Kashi Maru was built in 1940 at the Osaka Iron Works. The ship was unloading a cargo of fuel and vehicles when she was attacked and sunk by USAAF B-25 bombers, escorted by USN F4U fighters.

The site of the shipwreck is popular for divers, and was featured in the Nature episode "War Wrecks of the Coral Seas".