The Swell Season originally refers to the 2006 album by Irish musician Glen Hansard and Czech singer and pianist Markéta Irglová. The title of the album as well as of the song "The Swell Season" is inspired by Hansard's favourite novel by Josef Škvorecký from 1975 bearing the same title.

Since their mutual rise to prominence after starring in the 2007 film Once, they increasingly referred to themselves as "The Swell Season" in promotion of their performances until it has unambiguously become the formal name of their collaboration in 2008. (Notably, they still used their separate names when they contributed their cover of Bob Dylan's "You Ain't Goin' Nowhere" to the 2007 soundtrack of I'm Not There.)

The initial album came about after Glen and Marketa were approached by the Czech film director Jan Hřebejk while touring in the Czech Republic, and were asked by him to record songs for his upcoming film Beauty in Trouble. It was the first album that Hansard, the singer for The Frames, had released independently of his band.

Some of the tracks on this album have appeared on other recordings - the track "Falling Slowly" and "When Your Mind's Made Up" on The Frames' album The Cost, and "Falling Slowly", "When Your Mind's Made Up", "Lies" and "Leave" on the Once soundtrack.