Best in the World (2018) was a professional wrestling pay-per-view event produced by Ring of Honor (ROH). It took place at the UMBC Event Center in Catonsville, Maryland on June 29, 2018. It was the ninth annual ROH Best in the World event. Wrestlers from New Japan Pro-Wrestling (NJPW), and Japanese women's promotion World Wonder Ring Stardom - with whom ROH has partnerships - also appeared on the card.

Brett Giehl, better known by the ring name Dalton Castle, is an American professional wrestler. He is currently signed to Ring of Honor (ROH), where he is a one-time ROH World Champion, a one-time ROH World Television Champion and a two-time ROH World Six-Man Tag Team Champion. He also makes appearances for its sister company All Elite Wrestling (AEW). He is also known for his tenure in Chikara, where he wrestled under the ring names Ashley Remington and Dalton Caroline Castle.