The title track was released as the album's lead single on November 3, 2018, peaking atop the charts of 12 countries and becoming Grande's first number-one single on the US Billboard Hot 100. The track also broke a string of records, including the record for the most plays in a single day by a female artist on Spotify. Its second single, "7 Rings", was released on January 18, 2019, peaking at number one in 15 countries and making Grande the third female artist to have two or more songs debuting atop the Hot 100. "Break Up with Your Girlfriend, I'm Bored" was released as the third single on the day of the album's release. The track's debut atop of the UK Singles Chart made Grande the first female artist to replace herself at number one on the chart, dethroning her previous single. In support of both Sweetener and Thank U, Next, Grande embarked on the Sweetener World Tour, beginning on March 18, 2019.
Upon its release, Thank U, Next received universal acclaim from music critics, many of whom praised the cohesiveness and production of the album. Commercially, the album peaked atop the charts of many countries, including Australia, Austria, Canada, Denmark, Ireland, New Zealand, Norway, Sweden, the United Kingdom and the United States. In the latter, the album broke the record for the largest streaming week for a pop album, debuting with 360,000 album-equivalent units.
In September 2018, Grande's ex-boyfriend, rapper Mac Miller, died from a drug overdose. The following month, Grande announced that she would take a break from music. That same month, however, Grande revealed that she had been in the studio working on new music, and she announced the Sweetener World Tour (2019). She stated that the tour would support both her fourth studio album, Sweetener (2018), and her upcoming fifth studio album. Later in October 2018, Grande broke off her engagement with comedian Pete Davidson.