Satoru Kitaoka (Japanese: 北岡悟, Kitaoka Satoru; born 4 February 1980), is a Japanese shoot wrestler and mixed martial artist who most recently competed for RIZIN. A professional competitor since 2000, he has also competed for DREAM, Pancrase, DEEP, and World Victory Road. Kitaoka is renowned for his catch wrestling abilities which he learned studying under two of Japan's most respected catch wrestlers Masakatsu Funaki and Minoru Suzuki. He is also a Brazilian jiu jitsu blackbelt under Yuki Nakai. A master of the guillotine choke and leg lock submissions, Kitaoka holds notable wins over Takanori Gomi, Paul Daley, and Carlos Condit.

Kitaoka became interested in mixed martial arts after seeing Bas Rutten and Masakatsu Funaki fight in Pancrase in 1996. In addition to mixed martial arts success, Kitaoka has also won several submission grappling tournaments, including being an All Japan Combat Wrestling champion and Brazilian jiu-jitsu and No-Gi Open Champion in weight and absolute.

Kitaoka spends his time taking care of his body, getting massages three times a week, utilizing saunas, and carbonated and ice baths. He also enjoys spending time on social media. Kitaoka also teaches at his gym and coaches his teammates.

Renowned originally for his catch wrestling abilities, Kitaoka made his professional debut for Pancrase on October 31, 2000, losing via majority decision. After submitting then 3-0 Kurt Pellegrino, Kitaoka drew with Heath Sims before losing to Katsuya Inoue. After picking up two wins to start 2005, Kitaoka improved to 12-6-8 before he faced future UFC interim welterweight champion Carlos Condit on October 2, 2005. Kitaoka defeated Condit in an upset, submitting him with a heel hook at 3:57 of the first round.

A leg lock specialist, Kitaoka would improve to 19-7-9 before facing Katsuya Inoue on January 30, 2008 for the third time after being defeating in their first meeting and a draw in the previous bout. Kitaoka lost via split decision.

After signing with World Victory Road, Kitaoka's first fight for Sengoku was a submission win over Ian James Schaffa at Sengoku 2 on 18 May 2008 before entering Sengoku's eight-man lightweight tournament. In the first round of the tournament at Sengoku 4 on 24 August 2008 he was put up against American Clay French. Kitaoka made short work of French, winning by submission due to an achilles lock at 1:21 of the first round. The win put him up against fellow Japanese fighter Eiji Mitsuoka in the tournament's semifinal taking place at World Victory Road Presents: Sengoku 6. Kitaoka again made short work of his opponent winning by a heel hook submission at 1:16 of the first round. The win earned him a place in the tournament's final taking place that same night against Kazunori Yokota. The fight proved longer than Kitaoka's three previous fights as it went the distance completing all three five-minute rounds with Kitaoka being awarded the unanimous decision, thus winning the 2008 Sengoku Lightweight Grand Prix.

The Lightweight tournament win set up Kitaoka to fight the last reigning PRIDE Lightweight Champion, Takanori Gomi, for Sengoku's newly created Sengoku Lightweight Championship. The two fought at Sengoku no Ran 2009 on 4 January 2009 and ended with Kitaoka defeating Gomi with an achilles lock at 1:41 of the first round.

In his first title defence, on August 2, 2009, at World Victory Road Presents: Sengoku 9, Kitaoka lost his lightweight championship to Mizuto Hirota.