 Evan McGuireBrendan (voice) | Brendan (voice) |
 Christen MooneyAisling (voice) | Aisling (voice) |
 Brendan GleesonAbbot Cellach (voice) | Abbot Cellach (voice) |
 Mick LallyAidan (voice) | Aidan (voice) |
 Liam HouricanBrother Tang / Leonardo (voice) | Brother Tang / Leonardo (voice) |
 Paul TylakBrother Assoua (voice) | Brother Assoua (voice) |
| MMichael McGrathAdult Brendan (voice) | Adult Brendan (voice) |
 Paul YoungBrother Square (voice) | Brother Square (voice) |
 Nora TwomeyAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| AAlli McCannAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| CClair FunchionAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| CConor O'HalloranAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| GGaelle HersentAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| MMarie ThorhaugeAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
 Sean Ono LennonAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| JJonas HoffmannAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| FFabian ErlinghäuserAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
| KKairen WalochAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
 James William O'HalloranAdditional Voices and Walla (voice) | Additional Voices and Walla (voice) |
