Nezumi may refer to the following:
Real life The Japanese word 鼠 meaning "rat" or "mouse" Nezumi Kozō was the nickname of a thief in the 19th century Previous name of Yuuki Matsuda
Software Now-defunct Ragnarok Online server emulator fork of Athena, released under the GNU General Public License written by Mark Karpeles.
Fiction Nezumi, race of anthropomorphic rat creatures in the Magic: The Gathering and Legend of the Five Rings trading card games Nezumi, one of the two main characters of the novel, manga and anime No. 6 Nezumi (One Piece), a minor character in the Japanese anime and manga One Piece Nezumi, a character in Majisuka Gakuen, portrayed by Mayu Watanabe.