France won the deciding doubles rubber to claim a first Fed Cup title since 2003 in Perth, Australia.
Kristina Mladenovic and Caroline Garcia beat Ashleigh Barty and Samantha Stosur 6-4 6-3 to seal a 3-2 victory, denying Australia a first Fed Cup in 45 years.
Earlier, Mladenovic defeated Barty in the singles but Ajla Tomljanovic beat Pauline Parmentier to level.
"I'm the proudest man on the planet. I am going to have a lot of beers," said French captain Julien Benneteau.
"I'm so proud of my girls and my team. They deserve it because they fought for a long time for this title."
Mladenovic and Garcia embraced on the floor on the baseline after the winning point, with their team racing to pile on top of them as France won the Fed Cup for a third time.
"I'm not sure I've completely realised, because it's been a crazy weekend for everyone," Garcia said. "The doubles went very fast, but we played every point so focused, and we played a great match and it was very tense."
Australia have now lost the last nine Fed Cup finals they have played in.
The final marked the last Fed Cup played under the current format, with an overhaul next year seeing 12 nations compete in a six-day event in Budapest.
That will mean an end to home ties and the atmosphere they bring, with the 26,951 fans turning up over two days in Perth the second-highest Fed Cup attendance on record after Roland Garros (30,000) in 2005.