Evan McGuire as Brendan (voice)

Christen Mooney as Aisling (voice)

Brendan Gleeson as Abbot Cellach (voice)

Mick Lally as Aidan (voice)

Liam Hourican as Brother Tang / Leonardo (voice)

Paul Tylak as Brother Assoua (voice)

Michael McGrath as Adult Brendan (voice)

Paul Young as Brother Square (voice)

Nora Twomey as Additional Voices and Walla (voice)

Alli McCann as Additional Voices and Walla (voice)

Clair Funchion as Additional Voices and Walla (voice)

Conor O'Halloran as Additional Voices and Walla (voice)

Gaelle Hersent as Additional Voices and Walla (voice)

Marie Thorhauge as Additional Voices and Walla (voice)

Sean Ono Lennon as Additional Voices and Walla (voice)

Jonas Hoffmann as Additional Voices and Walla (voice)

Fabian Erlinghäuser as Additional Voices and Walla (voice)

Kairen Waloch as Additional Voices and Walla (voice)

James William O'Halloran as Additional Voices and Walla (voice)