3. BLACKPINK 2018–2019: International recognition, Blackpink in Your Area and world tour

In January 2018, it was announced that the debut Japanese EP of the group would be re-released under the name Re:Blackpink. The digital version included the same songs as the original release, while the physical version included a DVD containing all music videos and six songs in the Korean language.

On June 15, 2018 the group released their first EP titled Square Up. The single "Ddu-Du Ddu-Du" from the EP debuted at number 17 on the Official Trending Chart in the United Kingdom, making them the first female K-pop group to enter the chart since its launch in 2016. The single also debuted as the highest-charting Hot 100 hit ever by an all-female K-pop act, opening at number 55 with 12.4 million U.S. streams and 7,000 downloads in the tracking week ending June 21, 2018. The single also debuted at number 39 on the US Streaming Songs tally, where Blackpink became the first K-pop girl group to chart a title. Square Up also brought the group their first entry and the highest-charting to date (2018) by an all-female K-pop group on the US Billboard 200, debuting at number 40 with 14,000  album-equivalent units, surpassing label mate 2NE1's 2014 record with their last album Crush which peaked at number 61. The EP also topped the Billboard World Albums chart. In South Korea, Square Up debuted at number one on Gaon Albums Chart. The single "Ddu-Du Ddu-Du" peaked at number one on the Digital, Download, Streaming and Mobile charts on Gaon in its second week, while "Forever Young" managed to peak under top five. YouTube's official tally saw the music video for "Ddu-Du Ddu-Du" garner a total of 36.2 million views within 24 hours after its release and became the most viewed online video in the first 24 hours by a Korean act and the second most watched music video of all time as at June 2018.

On July 7, the final stop of the tour was added for December 24 at Kyocera Dome Osaka as a Christmas gift for their fans, which made them the first overseas girl-group to perform at a domed stadium in Japan. They embarked on their first Japan tour, Blackpink Arena Tour 2018, in Osaka on July 24–25. On September 12, it was announced that the group would hold their first concert in Seoul titled "Blackpink 2018 Tour [In Your Area] Seoul x BC Card" at Olympic Gymnastics Arena.

In September 2018, English singer Dua Lipa announced "Kiss and Make Up", a collaboration with Blackpink for the re-released Complete Edition of her self-titled debut album in October 19, 2018. "Kiss and Make Up" debuted at number 93 at the Billboard Hot 100, marking the Blackpink's second entry in the chart, and making them the only Korean girl group as at October 2018 to score multiple entries on the chart. The song is also their second song in the UK Singles Chart, peaking at number 36. It is also their first Top 40 entry, thus, making them the first female K-pop group and third Korean act overall to reach the chart's Top 40.

In October 2018, YG CEO Yang Hyun-suk announced that each Blackpink member would have solo projects, with Jennie debuting first and Rosé next. On the same month, the group signed with Interscope Records for a global partnership with YG Entertainment; they would be represented by Interscope and Universal Music Group outside of Asia. In November 2018, Blackpink announced additional tour dates for their In Your Area World Tour, which covers thirteen dates around Asia from January through March 2019. Jennie debuted her solo single, "Solo", at Blackpink's Seoul concert on November 11; both the song and its official music video were released the following day. Their first Japanese studio album, Blackpink in Your Area, was made available digitally on November 23, and physically on December 5, 2018. The album debuted at no. 9 on the Japanese album chart, selling an estimated 13,000 copies in its first week.

Blackpink made their American debut at Universal Music Group's 2019 Grammy Artist Showcase, which was invite-only and took place at ROW in Downtown Los Angeles on February 9. The group has since appeared in several American television shows in February 2019. Billboard's March issue had with five covers, a group cover and four with each individual member. They are the first K-pop girl group to be on the magazine's cover.

Blackpink's second EP, Kill This Love, was released on April 5, 2019. Blackpink performed at the 2019 Coachella Festival on April 12 and 19, 2019, being the first female K-pop group to perform at Coachella. The EP debuted at no. 24 on the Billboard 200, while the single reached no. 41 on the Billboard Hot 100. "Kill This Love" made it on to Billboard's staff-curated list of the 100 Best Songs of 2019, takes No. 66 on the list, with Billboard writing, "If there were doors remaining for Blackpink to bust through, they were evaporated by the first horn blasts of 'Kill This Love', a song that sounds practically biblical in its sonic might."

The song "Forever Young", released as a track from the EP Square Up (2018), surpassed 2.5 million downloads on December 2019, making it the group's fifth song overall and their second to achieve a Platinum certification for downloads from the Korea Music Content Association (KMCA).