A considerable amount has been written on the policing and surveillance of the Irish communities in Australia in the 1910s-1920s, with the monitoring of those with Irish Republican sympathies during the Anglo-Irish War. However much less has addressed Irish Republicanism in Australia in the post-war era, especially during the 'Troubles' which lasted from 1969 to 1998. In this time, a multitude of groups and individuals with ties to Australia's Irish communities, as well as political organisations on both the left and Catholic right, supported Irish Republicanism to some extent, with rallies, meetings and fundraising events. This paper will examine the files released by the National Archives in Canberra relating to the surveillance of these groups and activists by ASIO, beginning in the late 1950s (during the IRA border campaign). As part of a wider project looking at the monitoring of 'suspect communities' in Australia during the 20th century, this paper will explore how Australia's security services monitored a wide range of people and organisations that were engaged in activism relating to a 'foreign' conflict at a time when the security services were shifting from a focus on political subversion and espionage to counter-terrorism.