Bright, who won gold in Vancouver four years ago, was narrowly beaten by Kaitlyn Farrington from the United States.
Kelly Clark, also from the US, claimed the bronze medal with Wednesday night's final run.
Bright's silver is Australia's first medal of the 2014 Games.
In her first attempt in the final, the woman from NSW started with a massive McTwist but couldn't complete what was looking like a high-scoring run.
However, after that disappointing run she came out with a big, technical second showing that scored 91.50 from the judges.
It left her agonisingly close to Farrington on 91.75.
Some commentators thought Bright had done enough to win, but the Australian was all smiles during the medal ceremony, blowing kisses to the crowd, dancing and waving.
The silver medal follows a seventh place in the slopestyle earlier in the week.
Bright, 27, is the first snowboarder to target three disciplines at a Games with the snowboard cross still to come.
Her busy schedule had some worried that Australia's best-known winter sports star was spreading herself too thin - particularly as the race-based snowboard cross is in stark contrast to the trick routines of the park and 'pipe.
Before Wednesday night she also seemed at times pre-occupied with external issues.
She wasn't happy with the slopestyle course or the condition of the halfpipe and before the Games suggested she might not even attend if terrorism threats worsened.