All About That Bass

"All About That Bass" is the debut single by American singer-songwriter Meghan Trainor, released on June 30, 2014, through Epic Records. The song was included on Trainor's debut extended play (EP), Title (2014), and her debut studio album of the same name (2015). The track, a bubblegum pop, doo-wop and hip hop record, was recorded from 2012 to 2013 at the Carriage House, based in Nolensville, Tennessee, and Sun Mountain Studios, based in Boiceville, New York. It was written by Trainor herself, alongside Kevin Kadish, who also produced the song. Trainor, who as a teenager struggled with her negative body image, was inspired to write the song to promote self-acceptance and body positivity.

Upon its release, some music critics praised "All About That Bass"'s production and memorable message, while others called it a novelty song and criticized the failure of its lyrics to empower every body type. The song was nominated for numerous awards and accolades, including Record of the Year and Song of the Year at the 57th Annual Grammy Awards. It was the best-selling song by a female artist during the 2010s in the United States, and was certified Diamond by the Recording Industry Association of America (RIAA). It also reached number one in 18 additional countries and received Diamond certifications in Australia, Brazil, and Canada, as well as multi-platinum certifications in Denmark, Italy, Mexico, New Zealand, Norway, Sweden, Spain, and the United Kingdom, becoming the fourth best-selling song of 2014 with 11 million copies sold worldwide.

Fatima Robinson directed the song's music video, which features 1950s-inspired aesthetics and a pink pastel backdrop. The video was released on June 10, 2014, and played an important role in the song's rise to prominence. "All About That Bass" inspired parodies and cover versions, such as a parody from the cast of This Hour Has 22 Minutes, and covers from The Roots, Avi Kaplan of Pentatonix, and Maejor with Justin Bieber. Trainor performed the song on television shows and broadcasts such as The Tonight Show Starring Jimmy Fallon, the 48th Annual Country Music Association Awards (with Miranda Lambert), and The X Factor UK, and included it on the set lists of her concert tours That Bass Tour and MTrain Tour (2015), the Untouchable Tour (2016), and the Timeless Tour (2024).