The 2018 Royal Rumble was the 31st annual Royal Rumble professional wrestling pay-per-view (PPV) and livestreaming event produced by WWE. It was held for wrestlers from the promotion's Raw and SmackDown brand divisions. The event took place on January 28, 2018, at the Wells Fargo Center in Philadelphia, Pennsylvania. It was the third Royal Rumble held at this venue after the 2004 and 2015 events, and was the first to include a women's Royal Rumble match, and consequently, two Royal Rumble matches, which is now standard for the event.

Traditionally, the Royal Rumble match winner receives a world championship match at that year's WrestleMania. With the introduction of a women's Royal Rumble match, two Royal Rumble matches were contested on the card with the winners of each receiving a choice of which championship to challenge for at WrestleMania 34. The men could choose to challenge for either Raw's Universal Championship or SmackDown's WWE Championship, while the women had the choice between the Raw Women's Championship and the SmackDown Women's Championship.

In total, nine matches were contested at the event, including three on the Kickoff pre-show. In the main event, Raw's Asuka won the first-ever women's Royal Rumble match by last eliminating SmackDown's Nikki Bella. This was also the second women's match to main event a WWE pay-per-view, and the first to main event one of WWE's "Big Four" pay-per-views. The men's Royal Rumble match was won by SmackDown's Shinsuke Nakamura, who last eliminated Raw's Roman Reigns. Other prominent matches included Brock Lesnar retaining Raw's Universal Championship in a triple threat match against Braun Strowman and Kane, and AJ Styles retained SmackDown's WWE Championship against Kevin Owens and Sami Zayn in a handicap match. The event was also notable for the surprise debut of former UFC mixed martial artist Ronda Rousey following the women's Rumble match, officially confirming that she had signed full-time with WWE. This also marked the last time a Royal Rumble event was held in a traditional arena, as every subsequent event has been held in a stadium.