Dominion 6.21 was a professional wrestling pay-per-view (PPV) promoted by New Japan Pro Wrestling (NJPW). The event took place on June 21, 2014, in Osaka, Osaka, at the Bodymaker Colosseum. The event featured nine matches, five of which were contested for championships. It was the sixth event under the Dominion name.

Dominion 6.21 featured nine professional wrestling matches that involved different wrestlers from pre-existing scripted feuds and storylines. Wrestlers portrayed villains, heroes, or less distinguishable characters in the scripted events that built tension and culminated in a wrestling match or series of matches.

In the first title match, Time Splitters (Alex Shelley and Kushida) defeated The Young Bucks (Matt Jackson and Nick Jackson) to win the IWGP Junior Heavyweight Tag Team Championship for the second time. This rematch from February's The New Beginning in Osaka was a result of the first day of the 2014 Best of the Super Juniors, where Shelley and Kushida scored back-to-back wins over Nick and Matt, respectively. In the second title match, Tencozy (Hiroyoshi Tenzan and Satoshi Kojima) made their third successful defense of the NWA World Tag Team Championship against former champions, K.E.S. (Davey Boy Smith Jr. and Lance Archer). The third title match saw Kota Ibushi make his fourth successful defense of the IWGP Junior Heavyweight Championship against the winner of the 2014 Best of the Super Juniors, Dragon Gate representative Ricochet. Post-match, Ibushi was challenged by both Kushida and El Desperado. This led to a title match on July 4 at Kizuna Road 2014, where Kushida defeated Ibushi to become a double champion. Dominion 6.21 also featured a follow-up to Back to the Yokohama Arena, where Takashi Iizuka turned on Toru Yano and jumped to Suzuki-gun. Iizuka teamed with Suzuki-gun leader and Yano's longtime rival Minoru Suzuki to defeat Yano and his new partner Kazushi Sakuraba, who had surprisingly saved Yano from the two on June 8.