The appearance of the fleet coincides with Vladimir Putin's arrival at the G20 summit in Brisbane this weekend and follows a highly anticipated exchange between the Russian leader and Australian premier Tony Abbott in Beijing.
Putin's presence in Brisbane was questioned given Australia's anger at the downing of Malaysia Airlines flight MH17 in July, in which 298 people died in rebel-held eastern Ukraine, including 38 Australian citizens and residents.
"Defence is monitoring Russian naval vessels that are currently transiting through international waters to the north of Australia," the Australian Defence Force said in a statement.
Australian media reports said they include a "heavily armed" cruiser and destroyer, a tug boat and a refuelling vessel.
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Australia said the Russian navy has previously been deployed in conjunction with major international summits. A warship from Russia's Pacific Fleet accompanied former Russian president Dmitry Medvedev's visit to San Francisco in 2010.
"This is a show of force, a stage-managed event and is all for show," he told AFP.
"People don't go around doing this unless they feel insecure and need to assert themselves. It's consistent with Putin's chest-out, posturing behaviour. It bolsters his domestic credentials."
Abbott famously vowed to "shirtfront" Putin -- an Australian Rules football term in which a player charges an opponent -- in Brisbane over the downing of MH17.