The 2018 Fastlane was the fourth Fastlane professional wrestling pay-per-view (PPV) and livestreaming event produced by WWE. It was held exclusively for wresters from the promotion's SmackDown brand division. The event took place on March 11, 2018, at the Nationwide Arena in Columbus, Ohio. The 2018 event was the final SmackDown-exclusive pay-per-view and subsequently the final brand-exclusive pay-per-view under the second brand split as following WrestleMania 34 in April, WWE discontinued brand-exclusive PPVs.

Seven matches were contested at the event, including one on the Kickoff pre-show. In the main event, AJ Styles retained the WWE Championship in a six-pack challenge against Kevin Owens, Sami Zayn, Baron Corbin, Dolph Ziggler, and John Cena. In other prominent matches, Randy Orton defeated Bobby Roode to win his first United States Championship, becoming the eighteenth Grand Slam Champion in the process, and Charlotte Flair retained the SmackDown Women's Championship against Ruby Riott, after which, women's Royal Rumble winner Asuka from the Raw brand made her SmackDown debut to challenge Flair for the title at WrestleMania 34.