IWGPジュニアヘビー級王座
Ospreay participated in the 2019 edition of Best of the Super Juniors, where he won his block with a record of 7–2, advancing to the final. In the preliminary rounds, he suffered losses against long-time rivals Robbie Eagles and El Phantasmo. On 5 June Ospreay defeated Shingo Takagi to win the tournament for the second time, earning an IWGP Junior Heavyweight Championship match at Dominion. The match between Ospreay and Shingo was awarded a 5.75 rating by Dave Meltzer of the Wrestling Observer Newsletter, the highest rating for a wrestling match in 2019. This was also the first match in which Shingo Takagi was pinned after his debut in NJPW. At Dominion, Ospreay defeated Dragon Lee and became IWGP Junior Heavyweight Championship for the third time in his career. With this wrestling match being awarded 5 stars, Dave Meltzer and Bryan Alvarez suggested that Will Ospreay has reached a point in his career where he is a serious contender for being the best wrestler in the world. After winning the title, Ospreay announced his intention to enter the G1 Climax 29 in his quest of bridging the gap between heavyweight and junior heavyweight wrestlers. Later that week, Ospreay was announced as a participant in the 2019 G1 Climax. Ospreay made his first IWGP Junior Heavyweight Championship title defense against Robbie Eagles at Southern Showdown in Melbourne.