Don't Smile at Me (stylized as dont smile at me) is the debut extended play by American singer Billie Eilish, released on August 11, 2017, via Darkroom and Interscope Records. Eilish and her brother Finneas O'Connell wrote most of the material on the EP and were solely responsible for its production. It is an electropop and bedroom pop record with elements of R&B and jazz.

Seven singles were released to support Don't Smile at Me. "Ocean Eyes" and "Idontwannabeyouanymore" were both sleeper hits, charting on the US Billboard Hot 100 and UK Singles Chart. "Bellyache" reached the top five on the Billboard Bubbling Under Hot 100 chart for a milestone of 32 weeks, while "Copycat" peaked at number 12 on the chart. Eilish embarked on the Don't Smile at Me Tour and Where's My Mind Tour in 2017 and 2018, respectively, to further promote the EP.

The EP received generally favorable reviews from music critics, with many praising the music and Eilish's vocals. "Hostage" received a nomination for Best Cinematography at the 2019 MTV Video Music Awards. Don't Smile at Me was commercially successful, reaching number 14 on the US Billboard 200 and number 12 on the UK Albums Chart. It entered the top 10 in many other countries, including Lithuania, where it reached number one.

The EP was later reissued on December 22, 2017, to include the single, "&Burn" with Vince Staples. The song was certified gold in the United States by the Recording Industry Association of America (RIAA). An expanded edition of the EP was released on digital platforms and features two more previously released singles, "Lovely" with Khalid and "Bitches Broken Hearts". "Lovely" was commercially successful, peaking at number 64 on the Billboard Hot 100 and number 47 on the UK Singles Chart. "Bitches Broken Hearts" was certified platinum in the US and Canada by the RIAA and Music Canada (MC), respectively.