The note, which will replace its more bland predecessor from September 1, features a yellow Prickly Moses wattle flower and a colourful Eastern Spinebill native bird.
“Each banknote in the new series will depict a different species of Australian wattle and a native bird within a number of the elements,” Reserve Bank of Australia governor Glenn Stevens said in a statement.
“The designs are the culmination of a process of extensive consultation with subject-matter experts and the cash-handling industry, as well as qualitative research involving focus groups.”
But critics – from social media users to bird-lovers – were quick to express their disdain.
"Our new fivers look like vomit," one user wrote on Twitter, while another quipped: "A thousand monkeys with a thousand versions of Photoshop could never come up with something as hideous as the new Australian $5 note."
Some questioned why the same portrait of Queen Elizabeth II, which was drawn from photographs commissioned by the central bank in 1984, was used rather than a recent image of Australiaʼs head of state.
“New Australian $5 note really knocks years off the Queen,” tweeted Joanna Hall.
The bill even managed to raise the ire of bird lovers.
“Itʼs way off in terms of colouration,” Birdlife Australia's migratory shorebird programme manager Dan Weller told AFP, although the birdʼs shape and markings were fairly accurate.
“The way itʼs been shown on the note, the only two colours that are right on there are the black and the white.”
Eastern Spinebills – found on Australiaʼs east coast – have red eyes, black heads, gray wings and tails, white throats, and chestnut-coloured undersides.
But the new bill gives them a bluish underside with a bright blue, yellow, purple and pink wing.
One Twitter user tried to cash in on the lack of support for the new note, tweeting: “I like the new Australian $5 note. For those who hate it, feel free to hand the notes over to me #altruistic.”
The bill is being introduced to mark the 50th anniversary of the nationʼs conversion to decimal currency.