Desmond Eastwood was born in Belfast and is one of six siblings. Eastwood was educated at Friends' School Lisburn and went on to study law at Queens' University Belfast graduating with an Upper Second Class honours. He then enrolled at the Gaiety School of Acting, Dublin. He is best known for portraying Niall in the BBC3/ HULU hit series Normal People (2020) for which he received a Best Supporting Actor nomination at the Irish Film and Television awards.