Shinya Aoki (Japanese: 青木 真也, Hepburn: Aoki Shin'ya; born May 9, 1983) is a Japanese mixed martial artist, professional wrestler and grappler competing in ONE Championship's Welterweight division. He also competes in DDT Pro-Wrestling where he is a former three-time DDT Extreme Champion and former one-time KO-D Openweight Champion.

A professional competitor since 2003, he is noted for being the DREAM Lightweight Champion, former two time ONE Lightweight World Champion, former WAMMA Lightweight Champion and former Shooto Welterweight Champion. Aoki is an A-class Shootist and BJJ black belt, both under his long-term mentor Yuki Nakai, as well as a black belt Judoka. As of 2008, Aoki, along with DEEP champion Masakazu Imanari, and Sengoku champion Satoru Kitaoka have founded the "Nippon Top Team" as a group of elite Japanese grapplers competing in MMA.

Besides his MMA credentials, Aoki has garnered several submission grappling accolades including two All Japan Jiu-Jitsu Championships, a Japan Open Jiu-Jitsu Championship, a Budo Open Championship, and an ADCC Japan Championship.

Aoki described himself as a problem child while growing up, which caused him to be isolated by his classmates. He found relief joining the judo club while in elementary school. In junior high school, Aoki found himself still below the level of his training partners, so he multiplied his training time, visiting other clubs and teams in his free time. He also researched wrestling and sambo techniques in books and magazines, which would lead to his signature eclectic style. His hard work paid off and his coach proposed him to aim for the national team, but he rejected it to spite his coach for previously looking down on him. Aoki even changed schools to the Shizuoka Gakuen Junior and Senior High School so he would be in a rival team.

Despite his success in competition, Aoki was criticized due to his unorthodox grappling style. He described his judo career as, "a battle against the tacit notion that a judoka's favorite moves must be seoi nage, uchi mata and osoto gari". He was also criticized once when he a struck a victory pose during a tournament, a practice frowned upon in judo. Aoki competed in national championships, rising as a star of the judo club of Waseda University. Even although his clash against his more traditional partners and teachers continued, he would score victories with unusual techniques like tobi-juji-gatame, waki-gatame and kakato-jime.

However, his interest began to move to the more liberal format of mixed martial arts, becoming a fan of Kazushi Sakuraba for his popularity and victories against much heavier opponents in Pride Fighting Championships. Aoki's conflicts in the judo team would only worsen. He admitted he would be disruptive, even keeping submission holds on after his opponents tapped out so he could get revenge on them. While in third year of university, he was finally kicked out of the team, but he was already training in mixed martial arts by this point. He made his professional debut the same year.

Aoki initially joined the Judo-based RJJ gym before moving to Team Roken along with his longtime friend Masakazu Imanari, though he later moved to Paraestra Shooto Gym, where he trained under former Kosen representative Yuki Nakai. He earned both his A-class Shooto rank as well as his Brazilian Jiu-Jitsu black belt under Nakai, and became one of the team's main teachers.

Aoki had his MMA debut for DEEP in November 2003, winning a one night tournament by fast armbar submissions. He later would show further unorthodox grappling skills against veteran Seichi Ikemoto and Keith Wisniewski, who he defeated by breaking his arm with a standing wakigatame also known as a Fujiwara armbar. He also would face legendary Hayato Sakurai in a Shooto event, losing a decision which was seen as controversial. Aoki went to compete in both companies until 2007, also defeating Akira Kikuchi to win the Shooto Welterweight Championship.