The final member of the family, a male marmoset called Gomez, was found by police on Monday, having been abandoned on a vets' doorstep.
A female and a baby were retrieved on Sunday, and are already back at Symbio Wildlife Park, south of Sydney.
Two men have pleaded guilty to charges of dealing with proceeds of crime.
Brothers Jesse and Jackson George are not believed to have snatched the monkeys from their enclosure, but they were charged with trying to profit from the theft.
Pygmy marmosets - the world's smallest monkey species - command up to A$5,000 (Â£3,000, $3,700) on the black market.
Police found the men after a tip-off from the public. A desperate appeal for information had been launched by the zoo, amid fears that the baby marmoset would die within 48 hours if unable to feed from its mother.
The four-week-old was found when the Georges' car was pulled over at Appin, southwest of Sydney.
The female marmoset was found about 20km (12 miles) away in the Campbelltown area.
Australian newspaper The Daily Telegraph said the brothers had exchanged marmoset pictures with a third person via mobile phone, along with messages about how much a monkey could sell for.
"Ay, check out my monkey," wrote the third person, according to court documents. "That's mad bro. Wanna sell it bruh?" Jackson George replied.
The baby marmoset is now home and well, said Symbio Wildlife Park, after they reunited it with its mother.
"Mum cradled the baby straight into her arms and bub immediately began to feed," the zoo wrote in a statement on Facebook.
Police say they are continuing their investigation into the theft.  The zoo said the marmoset enclosure is currently closed "to give the family privacy".
Three rare pygmy marmosets have been rescued and are set to be reunited, after being stolen from a Sydney zoo at the weekend.