Nitty Gritty Dirt Band (sometimes abbreviated NGDB), known as the Dirt Band from 1978 to 1983, is an American band founded in Long Beach, California, in 1966. Since 2018, the band has consisted of Jeff Hanna and his son Jaime Hanna, both guitarists and vocalists, along with Jimmie Fadden (drums, harmonica, vocals), Bob Carpenter (keyboards, accordion, vocals), Ross Holmes (fiddle, mandolin, vocals), and Jim Photoglo (bass guitar, vocals).

Jeff Hanna and Fadden founded the band in 1966 with a lineup initially consisting of Bruce Kunkel, Ralph Barr, Les Thompson, and Jackson Browne, who quit early on and was replaced by longtime member John McEuen (vocals, guitar, banjo). The band had its first hit single in 1967 with "Buy for Me the Rain" on Liberty Records. Their earliest work featured jug band and traditional folk elements. In 1970, Nitty Gritty Dirt Band had their biggest pop hit with a cover of Jerry Jeff Walker's "Mr. Bojangles". The band's sound took on elements of soft rock in the latter half of the 1970s and early 1980s, including the hit singles "An American Dream" and "Make a Little Magic".

Starting in 1983, Nitty Gritty Dirt Band began a shift toward country music, led off by the singles "Shot Full of Love" and "Dance Little Jean". By this point, the band consisted of Jeff Hanna, McEuen, Fadden, Carpenter, and Jimmy Ibbotson (bass guitar, vocals). This lineup recorded several country albums for Warner Records throughout the 1980s and charted multiple singles on the Billboard Hot Country Songs. Of these, "Long Hard Road (The Sharecropper's Dream)", "Modern Day Romance", and "Fishin' in the Dark" all went to number one. After leaving Warner in the late 1980s, Nitty Gritty Dirt Band recorded for several other labels, including Universal, MCA Nashville, and DreamWorks Records. The band has collaborated with a number of artists, including Doc Watson, Linda Ronstadt, John Denver, and Steve Martin. In addition, Hanna co-wrote Rascal Flatts's 2005 single "Bless the Broken Road", which was originally recorded by Nitty Gritty Dirt Band.

Nitty Gritty Dirt Band has released three collaborative albums: Will the Circle Be Unbroken (1972), Will the Circle Be Unbroken: Volume Two in 1989, and Will the Circle Be Unbroken, Volume III in 2002. All three albums featured a large number of guests from folk, rock, country, and bluegrass. They have also won three Grammy Awards. The band's sound draws influence from country, pop, rock, bluegrass, and folk music, and has seen overall generally positive critical reception.