Nitty Gritty Dirt Band (sometimes abbreviated NGDB), also known as the Dirt Band, 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 Nitty Gritty Dirt 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". Their 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 the early 1980s, 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 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, with the latter becoming their signature song. After leaving Warner in the late 1980s, Nitty Gritty Dirt Band recorded for several other labels, including Universal, MCA Nashville, Rising Tide, and DreamWorks Records. They have collaborated with a number of artists, including Doc Watson, Linda Ronstadt, John Denver, and Steve Martin. In addition, Jeff Hanna co-wrote the song "Bless the Broken Road", the most successful version of which was recorded by Rascal Flatts.

Nitty Gritty Dirt Band is also known for three collaborative albums: Will the Circle Be Unbroken in 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. Critics have found influences of country, pop, rock, bluegrass, and folk music in their sound.