NXT TakeOver: Brooklyn 4 was the 21st NXT TakeOver and the fourth and final TakeOver: Brooklyn professional wrestling livestreaming event produced by WWE. It was held exclusively for wrestlers from the promotion's NXT brand division. The event aired exclusively on the WWE Network and took place on August 18, 2018, at the Barclays Center in Brooklyn, New York as part of that year's SummerSlam weekend.

Seven matches were contested at the event, including two taped for the August 22 episode of NXT. In the main event, Tommaso Ciampa defeated Johnny Gargano in a Last Man Standing match to retain the NXT Championship. In other prominent matches, Kairi Sane defeated Shayna Baszler to win the NXT Women's Championship, and Ricochet defeated Adam Cole to win the NXT North American Championship.