（松山ケンイチ，松山健一，1985年3月5日-），日本演员。他以对奇怪角色的亲和力而闻名，他最出名的是 2006 年电影《死亡笔记》、《死亡笔记 2：姓氏》和 2008 年的《L：改变世界》，以及在《死亡笔记》动画改编中为 Gelus 配音。2010年12月上映的村上春树小说《挪威森林》改编电影中饰演主角渡边彻。

Kenichi Matsuyama (松山 ケンイチ, Matsuyama Ken'ichi, born March 5, 1985) is a Japanese actor. He is known for his affinity for strange character roles, and he is best known internationally for playing L in the 2006 films Death Note, Death Note 2: The Last Name and L: Change the World in 2008, as well as voicing Gelus in the Death Note animated adaptation. He was cast to play lead character Toru Watanabe in the film adaptation of Haruki Murakami's novel Norwegian Wood, which was released in December 2010.