The IWGP Junior Heavyweight Tag Team Championship is a professional wrestling tag team championship owned by the New Japan Pro Wrestling (NJPW) wrestling promotion. "IWGP" is the acronym of NJPW's governing body, the International Wrestling Grand Prix. The title was introduced on August 8, 1998 at a NJPW live event. The IWGP Junior Heavyweight Tag Team Championship is not the only tag team title contested for in NJPW; the IWGP Tag Team Championship is also sanctioned by NJPW. According to NJPW's official website, the Junior Heavyweight Tag Team Championship is listed as an "IWGP Jr. Tag Class", while the IWGP Tag Team Championship is considered an "IWGP Heavy Weight Class". The title is contested for by junior heavyweight wrestlers; the weight-limit for the title is 220 lb (100 kg). Being a professional wrestling championship, the title is won as a result of a predetermined outcome.
Title changes happen mostly at NJPW-promoted events. The inaugural champions were Shinjiro Otani and Tatsuhito Takaiwa, who defeated Dr. Wagner, Jr. and Koji Kanemoto on August 8, 1998 in the finals of a tournament. Rocky Romero currently holds for the record of most reigns by an individual wrestler, with eight. At six reigns, The Young Bucks hold the record for the most by a team. Gedo and Jado's combined four reign lengths add up to 960 days—the most of any team. Separately, Gedo and Jado are tied for most days as champion. NJPW keep track of all championship title defenses per reign, which is unlike most mainstream wrestling organizations. They also hold the most total defenses as champions, with 15. Gedo and Jado separately are tied for the record of total defenses by a single wrestler. Gedo and Jado are tied with Liger and Kanemoto for most defenses during a single reign, at 6. Liger and The Great Sasuke's only reign and Minoru and Prince Devitt's first reign share the record for the fewest successful defenses, with zero. At 348 days, Otani and Takaiwa's second reign is the longest in the title's history. Minoru and Prince Devitt's first reign is the shortest, at 21 days. Overall, there have been 52 reigns shared among 41 wrestlers, who made up 31 different teams.
The Motor City Machine Guns (Alex Shelley and Chris Sabin), a Total Nonstop Action Wrestling (TNA) tag team, defeated then-reigning champions No Limit (Tetsuya Naitō and Yujiro) on January 4, 2009 at Wrestle Kingdom III. Their reign lasted until July 5, 2009, when they were defeated by Apollo 55 (Prince Devitt and Ryusuke Taguchi) at a live event. During that time, they had three successful defenses; two were held by TNA due to a pre-existing relationship and an agreement with NJPW. Their first defense in TNA, a rematch against No Limit, occurred on March 31, 2009 at the tapings of their weekly television program TNA Impact! On April 19, 2009, they made their second, and last, defense in TNA at the Lockdown (2009) pay-per-view event in a Three Way Tornado Tag Team Six Sides of Steel cage match against No Limit and The Latin American Xchange (Hernandez and Homicide).