Lucy Elizabeth Dacus (/ˈdeɪkəs/ DAY-kəss; born May 2, 1995) is an American singer-songwriter, guitarist, and record producer. Originally from Richmond, Virginia, Dacus first gained fame following the release of her debut album, No Burden (2016), which led to a deal with Matador Records. Historian, her second album, was released in 2018 to critical acclaim. Home Video, her third studio album, was released in 2021. Forever is a Feeling, her fourth album, was released in 2025.

In addition to her solo work, Dacus is also a member of the indie supergroup Boygenius, with Julien Baker and Phoebe Bridgers. The band has released one studio album and two EPs to critical acclaim and widespread touring. The band won three Grammy Awards in 2024, including Best Alternative Music Album. They also became the first all-female band to win Best Rock Song and Best Rock Performance.

In October 2023, Rolling Stone named Dacus the 213th-greatest guitarist of all time, noting: "[her] guitar is as essential an instrument as her voice".

Lucy Elizabeth Dacus was born on May 2, 1995. She was adopted as an infant and grew up in Mechanicsville, Virginia, a suburb of Richmond. She is of Uzbek and Irish descent. Her adoptive mother is a professional pianist and music teacher, and her adoptive father is a graphic designer. Dacus had an early interest in music, and bought her first guitar, an Ibanez, from Craigslist when she was in middle school. After graduating from Maggie L. Walker Governor's School in 2013, she began studying film at Virginia Commonwealth University, but left to avoid student debt and the "feeling of being misunderstood" in her university program. Prior to becoming a full-time musician, she was employed by Richmond Camera as an editor for children's school photos. During this time, she wrote approximately 30 songs, nine of which would make up the tracklist of No Burden.

Dacus first performed in New York City in March 2015. Her first single, "I Don't Wanna Be Funny Anymore", premiered in November 2015. Her debut album No Burden was produced in Nashville by her hometown friends, Berklee College of Music graduate Collin Pastore and Oberlin Conservatory of Music graduate Jacob Blizard; it was recorded at the request of Blizard for a school project. The album was originally released digitally on CD, and on vinyl via Richmond's EggHunt Records on February 26, 2016. Dacus was then signed to Matador Records, who re-released the album on September 9, 2016. In the same year she performed at Lollapalooza, in Chicago's Grant Park and made her national television debut on CBS This Morning. She recorded a Tiny Desk Concert for NPR the same weekend. In October 2016 she played the London Calling festival in Amsterdam, as a replacement for The Duke Spirit, who had been forced to cancel.

Dacus's second album, titled Historian, was released on March 2, 2018. Like its predecessor, it was met with widespread critical acclaim. Writing for Pitchfork, Sasha Geffen praised its nuance and sensitivity: "It’s not an easy album to wear out. It lasts, and it should, given that so many of its lyrics pick at time, and the way time condenses around deep emotional attachments to other people." Rolling Stone rated the album 4/5 stars, as did NME. Historian, like No Burden, was recorded in Nashville, at Trace Horse Studio, in a similar collaborative effort by Lucy Dacus, Jacob Blizard, and Collin Pastore.

In 2018, Dacus, Phoebe Bridgers, and Julien Baker, formed the supergroup Boygenius. In August, they released three songs from their self-titled debut EP, which was fully released on October 26, 2018.

To coincide with Valentine's Day 2019, Dacus released a cover of "La Vie en rose", the first in a planned series of songs commemorating major holidays.