Rounder Records is an independent record label founded in 1970 in Somerville, Massachusetts, by Marian Leighton Levy, Ken Irwin, and Bill Nowlin. Focused on American roots music, Rounder's catalogue of more than 3000 titles includes records by Alison Krauss and Union Station, George Thorogood, Tony Rice, and Béla Fleck, in addition to re-releases of seminal albums by artists such as the Carter Family, Jelly Roll Morton, Lead Belly, and Woody Guthrie. "Championing and preserving the music of artists whose music falls outside of the mainstream," Rounder releases have won 54 Grammy Awards representing diverse genres, from bluegrass, folk, reggae, and gospel to pop, rock, Americana, polka and world music. Acquired by Concord in 2010, Rounder is based in Nashville, Tennessee. In 2016, The Rounder Founders (Levy, Irwin and Nowlin) were inducted into the International Bluegrass Music Hall of Fame.

Rounder was founded by Ken Irwin, Bill Nowlin, and Marian Leighton Levy. Nowlin and Irwin first met in 1962 as incoming freshman at Tufts University in the Boston suburb of Medford, Massachusetts. Exposure to The Greenbriar Boys, the Charles River Valley Boys, the Hillbilly at Harvard radio show, and fiddling conventions, as well as the musicians who performed at Club 47, one of the first venues in the Northeast to book African-American blues artists from the American south, fueled their interest in bluegrass, old-time, and other roots music. They were unable to find records by many of the artists they saw live: the records "just didn't exist."

Nowlin and Irwin met Levy, then a student at Clark University, in 1967. An "unrepentant folkie," like Nowlin and Irwin, she moved to Boston to attend graduate school at Northeastern University. The three shared an apartment as well as a desire to bring roots music to a wider audience, and began to explore the idea of starting a record company. "We were all involved in radical politics, and the anti-war movement, and a lot of our inspiration for starting Rounder had to do with minority culture and wanting to represent music that we really liked, but that was not in the mainstream," Levy said in a 2015 interview.

Financed with Irwin's savings of $1500, Rounder was founded in 1970 in the Somerville apartment, a living/working/political collective. The name Rounder was chosen for several reasons: the shape of a vinyl record, the nickname for a hobo, and the name of the folk band The Holy Modal Rounders. Levy, Irwin and Nowlin also self-identified as "Rounders", the name reflecting the "outlaw self-image of three romantics who positioned themselves in opposition to capitalism, the programmatic rigidity of the old Left, and the more doctrinaire cultural rules of the folk revival itself." The lawyer who drew up Rounder's papers of incorporation did so in exchange for two Rounder albums.

Irwin and Nowlin were introduced to fiddle music through a Folkways recording of the 34th Old Time Fiddlers Convention, and in late 1969 (sources differ), for $125 ($1,072 in 2024), they bought the rights to a tape by a 76-year-old banjo player, George Pegram, who had been a star of the Fiddlers Convention. It became Rounder's first release, Rounder 0001. Rounder 0002 was by the Spark Gap Wonder Boys; a local band, the album was recorded at the Harvard and MIT radio stations for "the cost of the tape." 500 copies of each record were pressed. Both were released on October 20, 1970. To boost the label's credibility—and get local record stores to stock their releases—Irwin, Nowlin, and Levy started distributing other small folk labels, and began selling albums at music festivals.

In 1971, the label released its first bluegrass album, One Morning in May, by Joe Val and the New England Bluegrass Boys. Over the next several years, they released bluegrass albums by old-time artists (Snuffy Jenkins and Pappy Sherrill, Highwoods Stringband, and The Blue Sky Boys), traditional bluegrass artists (Don Stover, Ted Lundy, Del McCoury, The Bailey Brothers, Buzz Busby), and progressive bluegrass artists, most notably by Country Cooking and Tony Trischka.

Believing that "music doesn't discriminate," Nowlin, Irwin and Leighton-Levy sought out female artists, then a rarity in the bluegrass world, and in the early 1970s released albums by Hazel Dickens and Alice Gerrard, who recorded as Hazel & Alice, and Ola Belle Reed. By 1974, Rounder had put out 22 records, including the label's breakthrough album, Norman Blake's Home in Sulphur Springs. Realizing that Rounder was no longer a part-time pursuit, Irwin resigned from his job—he was a professor at the University of Lowell—and Nowlin and Levy left graduate school to run Rounder full-time.

In 1975, Rounder released the self-titled debut album by J. D. Crowe and The New South. Called one of the "most pioneering and influential records in the history of bluegrass" by allmusic.com, it was commonly referred to by its stock number, Rounder 0044. The program notes from the 2016 Bluegrass Hall of Fame Induction ceremony stated that the record "did much to chart the course of bluegrass for the balance of the 1970s and beyond."