Reynolds was born in Ballinamore, County Leitrim, to Patrick J. Reynolds and his wife Tess. He received his secondary education at Garbally College in Ballinasloe, County Galway. His father Patrick was a Fine Gael TD and senator, and his grandfather Patrick Reynolds had been a TD until his assassination in 1932, when his widow Mary Reynolds was elected to succeed him, and held the seat for 25 years.