on january 4, 2018, alexander was traded to the los angeles dodgers in a three team trade that also sent jake peter to the dodgers, luis avilán and joakim soria to the chicago white sox and trevor oaks and erick mejia to the royals. the dodgers used alexander as an opener on june 1 due to an injury to clayton kershaw. in his first season in l.a, alexander appeared in 73 games, allowing 27 earned runs in 66 innings for a 3.68 era. he appeared in four games in the postseason for the dodgers, one in the 2018 nlds and three in the 2018 world series, allowing two runs to score on one hit and two walks in 2 innings pitched.