Kazuo Matsui (松井 稼頭央, Matsui Kazuo, born October 23, 1975) is a Japanese retired professional baseball player who played as a shortstop and is the current manager of the Saitama Seibu Lions. He is a switch-hitter. Matsui signed with the New York Mets on December 17, 2003, becoming the first Japanese infielder to sign with a Major League Baseball team.