Bayley, who had pleaded guilty, was sentenced to life imprisonment with a minimum jail term of 35 years.
Ms Meagher, originally from County Louth, was attacked in Melbourne last September as she walked home.
The judge described Bayley as a "recidivist sex offender". Bayley was on parole for previous rape convictions when he attacked Ms Meagher.
The case has led to criticism of the parole system in Australia's Victoria state.
In an earlier hearing, the court was told that Bayley had a history of violent sex attacks.
Judge Geoffrey Nettle said Bayley's rape of Ms Meagher was "savage and degrading".
"This is a recidivist, violent sex offender who intended to kill and this killing is amongst the worst of its kind," he said.
However, he said that Bayley's guilty plea had to be taken into consideration in the sentence.
"As bad as your crimes are, you will have the opportunity in jail to strive for rehabilitation and I propose to set a non-parole period as an incentive for you to try."
In a statement, Ms Meagher's family said: "This despicable crime against Gillian has happened and it has taken nine months to get resolved and to get justice."
"The police and prosecutors have ensured that justice has been done and we as a family want to thank them for this."
Ms Meagher's husband, Tom, said in a statement last week that his life would "never be normal again".
"I miss her insight, fun and wit, her huge smile and infectious personality," he said.
Ms Meagher, who was originally from Drogheda, moved to Australia from Ireland in 2009 with her husband.
She worked for ABC Radio but went missing during a night out with colleagues.
Her body was discovered six days later buried on the outskirts of the city.
News of her death prompted thousands to take part in a rally against violence against women.

The benchmark US crude oil price is also at a four-year low, after losing $2.57 to close at $74.28.
The price has fallen sharply since the summer and is 30% below its June price.
The drop comes as traders believe members of the Opec oil exporting countries, which control about 40% of world oil exports. will not cut production.
Opec's 12 member countries will meet later this month to discuss the global oil market.
Lower oil prices typically prompt Opec nations, which include the biggest oil exporting nation in the world, Saudi Arabia, to rein back output in order to limit supply and boost prices and income.
Most need higher oil prices to fund rising government spending.
But recent comments by oil ministers from Saudi Arabia and Kuwait suggest the group is unlikely to agree to a cut.
The US energy department said this week that it expected low fuel prices to last into next year.
Australian Adrian Bayley has been jailed for the rape and murder of Irish woman Jill Meagher.
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The price of Brent crude oil has fallen $3.60 - 4.4% - to $77.52, its lowest level for four years.