In Part One, Join the formidable Dublin widow Agnes Brown and her hilarious family of five sons and one daughter as she plows through the preparations for the family wedding.
| Actor | Role |
|---|---|
 Brendan O'CarrollAgnes Brown | Agnes Brown |
 Jennifer GibneyCathy Brown | Cathy Brown |
 Rory CowanRory Brown | Rory Brown |
 Paddy HoulihanTrevor Brown | Trevor Brown |
 Danny O'CarrollSimon Brown | Simon Brown |
 Eilish O'CarrollHilliary Nicholson | Hilliary Nicholson |
| EEric O'CarrollBono Brown | Bono Brown |
 Fiona O'CarrollMaria Nicholson | Maria Nicholson |
 Marion O'DwyerSharon McGoogan | Sharon McGoogan |
| MMike PyattMr. Foley | Mr. Foley |
| CClyde CarrollDermot Brown | Dermot Brown |
| PPat BakerPhotographer | Photographer |
 Gay ByrneCourier | Courier |
| JJohn DouglasFactory Boss | Factory Boss |
 Keith DuffyVet | Vet |
| CConor EvansPriest | Priest |
| MMichael GibneyPatient | Patient |
| BBrendan KealySinbad Nicholson | Sinbad Nicholson |
| EElsie KeatingWelfare Woman | Welfare Woman |
 Ronan KeatingTaxi Driver | Taxi Driver |
| KKim LeeNurse #1 | Nurse #1 |
| CClare MullenWinnie McGoogan | Winnie McGoogan |
 Fionnuala MurphyBetty Brown | Betty Brown |
| OOrla PhillipsNurse #2 | Nurse #2 |
| MMatthew RyanBarman | Barman |
| DDermot StanleyDino Doyle | Dino Doyle |
 Pat ShieldsMark Brown | Mark Brown |