Roger Morrison has recently published a 408 page book dissecting the definition of what a comic is taking into account many varied international opinions to determine what the first Australian comic was.
Daniel Best wrote a great piece a couple years ago suggesting Vumps (1908) as a possible candidate.
The four page comic below was a Christmas supplement with the The Pictorial Australian published in 1885 and depicts an English visitors time at Coopers Crossing, South Australia. I have a fairly broad a opinion of what constitutes a comic but perhaps this publication would not be considered a comic as it published as a supplement and doesn't contain word balloons. It sure is pretty to look at though.