IWGP Heavyweight Championship

The IWGP Heavyweight Championship is a professional wrestling heavyweight championship owned by the New Japan Pro-Wrestling (NJPW) promotion. "IWGP" is the acronym of NJPW's governing body, the International Wrestling Grand Prix. The title was introduced on June 12, 1987, in the finals of a IWGP tournament. Being a professional wrestling championship, the title is won as a result of a predetermined outcome.

Throughout the history of the championship, several wrestlers have been forced to relinquish the title due to an inability to participate in title defenses. When a wrestler has been injured or unable to compete for other reasons, tournaments have been held to determine the new champion.

In 2006, Brock Lesnar was stripped of the title for being unable to defend it; however, Lesnar claims he was owed money by NJPW and kept the physical belt. He signed with Antonio Inoki's Inoki Genome Federation (IGF) in 2007, and lost the championship to Kurt Angle on the inaugural broadcast. Angle later lost the belt in a unification match to the NJPW-recognized champion Shinsuke Nakamura in 2008. The title forms what has unofficially been called the "New Japan Triple Crown" (新日本トリプルクラウン, Shin Nihon Toripuru Kuraun) along with the IWGP Intercontinental and NEVER Openweight Championships.

Overall, there have been 65 reigns shared among 27 wrestlers. Title changes happen at NJPW-promoted events. Six non-Japanese wrestlers have held the title. The inaugural champion was Inoki, who defeated Masa Saito on June 12, 1987, in a tournament final. Hiroshi Tanahashi holds the record for most reigns, with 7. At 489 days, Shinya Hashimoto's third reign is the longest in the title's history. Tanahashi, with a combined 7 reigns, holds the record for most days as champion at 1,358. Kensuke Sasaki's fourth reign holds the record for shortest reign at 16 days. With 11 successful defenses, Tanahashi's fifth reign had the most during a single reign. Over his 7 reigns, Tanahashi successfully defended the title 28 times, the most of any champion. With zero, Big Van Vader's first and third reigns, Salman Hashimikov's only reign, Riki Choshu's first reign, Tatsumi Fujinami's third and fifth reigns, Masahiro Chono's only reign, Genichiro Tenryu's only reign, Scott Norton's second reign, Hiroyoshi Tenzan's first and third reigns, Kensuke Sasaki's fourth reign, Kazuyuki Fujita's third reign, and Manabu Nakanishi's only reign are all tied for least successful defenses. Kazuchika Okada is the current champion in his fourth reign, after defeating Tetsuya Naito on June 19, 2016, at NJPW's Dominion 6.19 in Osaka-jo Hall event to win the title.