In March of 2015, the Atheist Foundation of Australia hosted atheist activists Matt Dillahunty, Aron Ra and Seth Andrews (under the tongue-in-cheek tour title, "The Unholy Trinity Down Under").
The speakers' presentations from Sydney, Brisbane and Melbourne are posted on AFA's tour website: http://www.unholytrinitydownunder.com
Special thanks to the AFA: http://atheistfoundation.org.au