When Spillane was an eight-year-old, his father died, leaving his mother to take over the running of the family pub while simultaneously raising a family of four children. Spillane was educated at the local national school and later attended St Brendan's College in Killarney, where one of his best friends was future Kerry teammate Páidí Ó Sé. At St Brendan's his football skills were developed. He played senior football with 'Brendan's' but lost both an All-Ireland Colleges' semi-final and a final.