Moran made his debut for the Republic of Ireland against Switzerland in 1980 and played a key role in Ireland's unsuccessful attempt to qualify for the 1982 FIFA World Cup finals in Spain. He played 71 times for Ireland between 1980 and 1994, including UEFA Euro 1988 in Germany and the 1990 FIFA World Cup in Italy, and scored 6 goals. He was also a member of the Irish squad at the 1994 FIFA World Cup in the United States, despite being 38 years old and about to retire from playing completely, but did not play due to an injury he picked up before the tournament started.