During his rugby playing career Paul played with UCC, Munster, Blackrock, Saracens, Leinster, Ireland and the British and Irish Lions.

Before retiring due to serious injury in 2003, Paul won 46 caps for Ireland and also played the full duration of all 3 tests in South Africa with the victorious 1997 British and Irish Lions. The 1997 Tour is seen as the definitive tour of the professional rugby era - the series was a unique victory against the odds. Paul was a very influential player in the winning of this series and was described by captain, Martin Johnson, as 'my player of the series'.

In addition, Paul is a member of an exceptional Irish sporting family - all 3 Wallace brothers have made the Guinness Book of Records as the only 3 members of one family to play for the Lions - a unique achievement in international sport'.