Bogaerts and the Red Sox agreed to a $7.05 million salary for the 2018 season. He began the 2018 season usually batting fifth in the lineup. He hit two grand slams in April; one on April 7 against the Tampa Bay Rays, and one on April 30 against the Kansas City Royals. Bogaerts was named AL Player of the Week for the week of July 2–8. He hit another grand slam on July 14, this one an extra-innings walk-off home run against the Toronto Blue Jays. For the regular season, Bogaerts had 23 home runs, 103 RBIs, and a .288 average. The Red Sox finished the year 108–54 and won the World Series over the Los Angeles Dodgers. Bogaerts was the only player to be on the Red Sox roster for both the 2013 and 2018 World Series.