Colin Farrell had several incidents with animals during the shoot. Jenny, the miniature donkey, kicked him while he was hand-feeding her. Second, the dog portraying Brendan Gleeson's pet bit him. Thirdly, a horse leading a cart Farrell was in sat in tried to reverse the cart into the ocean.
All of the main characters' sweaters were made by the same elderly woman, Delia Barry. She knitted them by hand specifically for the film, including doubles for each sweater. She was not present on set, and did not meet the actors prior to creating the pieces for them. Barry stated one of Colin Farrell's sweaters took 100 hours to complete.
The J.J. Devine Public House was purpose-built for the film's production on Achill Island in County Mayo on the west coast of Ireland. Since a planning permit had not been acquired, the pub had to be demolished when the film wrapped. However, the BBC reported on the 08/07/23 that the pub was saved by publican Luke Mee who relocated and reconstructed it in order to act as a tourist spot.
Brendan Gleeson is a skilled fiddle player in real life and plays his own music here just as he did in Michael Collins (1996), The Grand Seduction (2013), and Retour à Cold Mountain (2003).
Colin Farrell and Brendan Gleeson agreed to be in the film several years before it was greenlit.