The Australians had never won a Winter Olympic gold before Steven Bradbury's fortuitous success in the 1,000m speed skating final just two days ago.
But Camplin ensured a second honour by outscoring Canadian pair Veronica Brenner and Deirdra Dionne who claimed silver and bronze respectively.
Another Australian, former world champion Jacqui Cooper, had been the favourite to take gold before she broke her knee in a training accident last week.
Meanwhile, Switzerland's Evelyne Leu, who set a world record for the two-jumped combined total during qualifying, placed a disappointing 11th with 147.31 points.
Camplin said afterwards: "I have never won anything in my life and now I have got an Olympic gold medal.
"I'm disappointed (to finish 11th), but I did do well in qualifications so I'm
happy about that "
Evelyne Leu, Swiss skier
"It was not until the very end that I thought I might have won.
The 27-year-old added: "This is the craziest thing that's ever happened to me."
She was lying third after the first jump of the final round.
On her second jump she nailed a backward triple twisting double that earned 99.75 points and shot her to the top of the podium with a total of 193.47 points.
Still waiting for the score to flash up, she held her hands to her face as Australian flags and kangaroo banners waved.
"It still doesn't seem real, maybe I'll realize it when I'm on the podium," she added.
Meanwhile, Leu insisted that her record-breaking performance in the qualification stages made her Olympic experience worthwhile despite missing out on the medals.
"I'm disappointed (to finish 11th), but I did do well in qualifications so I'm happy about that. I was nervous and didn't have a lot of energy," she said.