Sierra Phương-Thảo Deaton is a singer, songwriter and dancer, from Philadelphia, Pennsylvania. Raised in Orlando, Florida, Deaton, through her father, Dr. John Deaton, claims British descent and through her mother, Vu Deaton, is of Vietnamese descent. She has an older sister named Lara Deaton. Deaton began dancing at the age of two and studied ballet, tap, jazz, hip hop, modern, and more. She competed for eleven years and won three international titles in Irish dancing. She attended Lake Howell High School. Deaton attended The University of Central Florida, studying for an advertising and public relations degree and graduating with honors in 2013.
Following the split of Alex & Sierra, Deaton began releasing music under the stage name, Essy. On 16 February 2018, Deaton released her debut solo single "Don't Hurt". She has since co-written songs and provided backing vocals for artists, including 5 Seconds of Summer for "Lover of Mine", Gnash for "forgive" and Lovelytheband for "coachella". Sierra Deaton is currently signed as a songwriter for Unknown Music Publishing and Kobalt Music Group.
Deaton is openly bisexual. Since 2018, Deaton has been dating Luke Hemmings of 5 Seconds of Summer. The couple announced their engagement on June 8, 2021, as confirmed on Instagram.
