Jun Akiyama (秋山 潤, Akiyama Jun; ring name: 秋山 準) (born October 9, 1969) is a Japanese professional wrestler, He is signed to DDT Pro-Wrestling, where he is a former KO-D Openweight Champion, former one-time DDT Extreme Champion, former four-time Ironman Heavymetalweight Champion and former KO-D Six Man Tag Team Champion. He is best known for his time with All Japan Pro Wrestling (AJPW), where he was the president, representative director, co-head booker, and an in-ring performer. In AJPW, he is a former two-time Triple Crown Heavyweight Champion and former longest reign one-time Gaora TV Champion, while also being a six-time overall professional wrestling world champion.

Akiyama is noted for his serious in-ring style and demeanor, innovating the Blue Thunder Driver and the wrist–clutch exploder suplex maneuvers. Considered an outstanding tag team wrestler, Akiyama is a three-time winner of the Wrestling Observer Newsletter Tag Team of the Year award.

In junior high school, Akiyama participated in swimming and in senior high school he competed in freestyle amateur wrestling and judo. After high school, he attended Senshu University in Tokyo, where he joined an amateur wrestling team that produced other professional wrestlers like Riki Choshu, Hiroshi Hase, and Manabu Nakanishi.

Akiyama is close friends with fellow AJPW and Noah alumni Kenta Kobashi, with whom he has a sarcastic backstage relationship.

Akiyama had great success as an amateur wrestler and was eventually scouted by All Japan Pro Wrestling (AJPW). He made his professional wrestling debut on September 17, 1992 in a match against Kenta Kobashi, which he lost. He gradually rose in rank, starting to team up with Akira Taue as part of what remained of Jumbo Tsuruta's team called "Tsuruta-Gun", earning a trial series in January 1993. Afterward, he started working tag teams. The tag team division soon became his speciality, teaming with Takao Omori against Kenta Kobashi and Mitsuharu Misawa. In January 1995, he split with Taue, and alongside Omori, won the All Asia Tag Team Championship, holding the belts for 1,076 days, until dropping them to Johnny Smith and Wolf Hawkfield on January 9, 1998, and also having the longest single reign in the history of those belts, even though sometimes he and Omori parted ways to team up with other wrestlers during that time. In early 1996, he was selected to be Misawa's partner after he split with Kobashi back in December. The two teamed together successfully and won the World Tag Team Championship during 1996. Akiyama and Misawa also competed in the World's Strongest Tag Determination League tournaments in 1996 and 1997, but lost in successive years to the team of Toshiaki Kawada and Akira Taue. Akiyama then began closing in on the Triple Crown Heavyweight Championship, first challenging Misawa in September 1997 and January 1998, Kobashi in July 1998, and Vader in January 2000. He was unsuccessful on all four occasions.

After teaming with Misawa, Akiyama began teaming with Kenta Kobashi to form 'Burning'. The team won numerous tag team titles and competed against the teams of Mitsuharu Misawa and Yoshinari Ogawa, Toshiaki Kawada and Akira Taue, Yoshihiro Takayama and Takao Omori and others. Burning also won the World's Strongest Tag Determination League tournament in 1998 by defeating the team of Stan Hansen and Vader, and again in 1999 by defeating Akira Taue and Stan Hansen. Akiyama's last major victory in All Japan Pro Wrestling was on February 27, 2000, when he defeated former tag team partner Mitsuharu Misawa by pinfall in a heated and highly acclaimed contest. His last match happened on July 20, where he and Jun Izumida lost to Takao Omori and Yoshihiro Takayama, and after that, he and other 25 wrestlers left to follow up Misawa to form Pro Wrestling Noah.

After a controversy in AJPW over the direction and management, he left the company with Mitsuharu Misawa, and half the roster, for Misawa's newly created Pro Wrestling Noah in mid-2000. Like many other members who made the jump, Akiyama gave himself a makeover, dropping his trademark blue and white trimmed boots and blue trunks for white boots and trunks and dyed his hair brown. He was quickly established as a top star of the company, winning both falls in the main event of Noah's first show, choking out Kenta Kobashi in the second Noah show the night after he turned heel for this first time in his career, and becoming the second GHC Heavyweight Champion, He had stellar title defenses in New Japan Pro-Wrestling against Yuji Nagata and Hiroshi Tanahashi. But a lack of worthy contenders eventually forced Noah to abandon his push, using Yoshinari Ogawa and Yoshihiro Takayama to transition the title back to Misawa. He continued work in Noah as a tag team competitor again to critical acclaim, winning the GHC Tag Team Championship with Akitoshi Saito.

In April 2004, he created the GHC Openweight Hardcore Championship to get back into singles competitions, and adapting an attitude manifested by wearing trunks that were odd colors for him. These motives helped put him back into contention for the GHC title against Kenta Kobashi, which was voted as Match of the Year. Late 2004 and much of 2005 were highlighted by his feud with protégé Makoto Hashi where Akiyama used "tough love" to toughen up young Hashi. On January 22, 2006, Akiyama defeated Akira Taue to become the GHC Heavyweight Champion for the second time, defending the title against Minoru Suzuki on March 5 and Masao Inoue on April 24. Akiyama was defeated by Naomichi Marufuji on Noah's September 9 Nippon Budokan show in his third defense of the GHC Heavyweight Title.