Tetuzi Akiyama (Akiyama Tetsuji) (born 13 April 1964) is a Japanese guitarist, violinist, and instrument-maker.
Akiyama formed the improvisation group Madhar in 1987, and the classical ensemble Hikyo String Quintet in 1994 (which also included Taku Sugimoto on cello). In 1995, Akiyama and Sugimoto formed a guitar duo, and played at venues in New York City, Chicago, and Detroit. During this time, Akiyama was also a member of Keiji Haino's Nijiumu outfit. Akiyama also formed Sutekina Tea Time (a duo with Takashi Matsuoka) and Mongoose (a trio with Taku Sugimoto and Utah Kawasaki).
In 1998 Akiyama began organising a monthly concert series, The Improvisation Meeting, with Toshimaru Nakamura. In December 2006 he began a regular duo with Hervé Boghossian (France), they toured in Europe (France, Portugal, Switzerland, England) several times in 2007 (in May, October and December) and also played in Tokyo during Hervé Boghossian Japanese tour in August/September 2008. In 2009 he worked with David Sylvian.