LEO CULLEN was educated at Blackrock College and University College Dublin. An Irish Schools, Under-19, Under-21, Under-25 and 'A' international, during the summer of 2002 he was included in the senior squad for the tour to New Zealand. On that trip he won his first cap when coming on as a replacement for Malcolm O'Kelly during the second Test in Auckland.

The following season (2002/03) he won another eight caps as a replacement in addition to making four starting line-ups. In August 2003, he won his 14th cap when playing in the World Cup warm-up game against Italy in Thomond Park. However he did not make the squad for the tournament itself. In 2004, he won another cap when coming on as a replacement against the United States and started both test matches against Japan on the '05 summer tour.

Cullen, who transferred from Leinster to Leicester Tigers that season, was recalled as a started against Romania in November '05. He won several titles with Leicester but he has since returned to Leinster and he subsequently won another cap against Argentina during the 2007 summer tour.