The Swell Season is a folk rock duo formed by Irish musician Glen Hansard and Czech singer and pianist Markéta Irglová.

"The Swell Season" name is derived from Hansard's favourite novel by Josef Škvorecký from 1975 bearing the same title.

(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.)

[8] The band provided and paid for group counselling sessions for concert attendees who witnessed the event.

On 10 and 11 January 2015, The Swell Season reunited for two concerts at Sejong Center[11] to celebrate re-releasing Once in South Korea.