Tsuyoshi Yokoyama (born June 29, 1983), better known as is a Japanese kickboxer who competes in the welterweight division. He comes from a Seidokaikan karate background and is known for his unorthodox kicks.
Yamamoto began practicing karate at the age of 13. His brother Shingo Yokoyama is also a kickboxer. In 2003 he became the 5th All Japan Seidokaikan Lightweight Champion.
He made his professional kickboxing debut on August 16, 2008, when he defeated Marcelo Nascimento by a unanimous decision. In his following fight he made his debut in the K-1 promotion at 'the K-1 World MAX 2009 World Championship Tournament Final 8 and was knocked out by Jae Gil Noh. Following this he went on an eight fight unbeaten run consisting of seven wins and one draw. He returned to K-1 in a tournament reserve match at K-1 World MAX 2011 -70kg Japan Tournament Final on September 25, 2011. He defeated Yoshi via a unanimous decision.
|- | |Win |align=left| Yoshi |K-1 World MAX 2011 -70kg Japan Tournament Final |Osaka, Japan |Decision (unanimous) |3 |3:00 |9-1-1 | |- | |Win |align=left| Kimuisaku |Gladiator 21 |Japan |KO (left hook to the body) |1 |2:27 |8-1-1 | |- | |Win |align=left| Yusuke Fukuda |HEAT 18 |Osaka, Japan |Decision (Unanimous) |3 |3:00 |7-1-1 | |- | |Win |align=left| Takeshi Yoshitsugu |ACCEL: Heavyweight Tournament Opening Round |Japan |KO (right hook) |2 | - |6-1-1 | |- | |style="background: #c5d2ea"|Draw |align=left| Kosuke Yamauchi | |Tokyo, Japan |Decision draw |3 |3:00 |5-1-1 | |- | |Win |align=left| Courage |Legend 1: Land of Fire |Japan |TKO |3 |0:29 |5-1 | |- | |Win |align=left| Shingo Takayama |Gladiator 11 |Japan |Decision (split) |3 |3:00 |4-1 | |- | |Win |align=left| |Gladiator 6 |Japan |TKO (corner stoppage) |2 |2:29 |3-1 | |- | |Win |align=left| Munjefun |Gladiator Okayama: Japan-Korea Friendship |Okayama, Japan |Decision (unanimous) |3 |3:00 |2-1 | |- | |Loss |align=left| Jae Gil Noh |K-1 World MAX 2009 World Championship Tournament Final 8 |Tokyo, Japan |KO (straight right) |3 |2:01 |1-1 | |- | |Win |align=left| Marcelo Nascimento |Gladiator: Korea Friendship International Martial Arts Tournament |Japan |Decision (unanimous) |3 |3:00 |1-0 | |- |- | colspan=10 | Legend: