The woman was walking along a bay in Melbourne on Monday night when she became distracted by her Facebook feed and plummeted off the pier into the chilly water, Victoria state police said.
A witness called for help and police rushed to the woman's aid. They found her flailing around in the water, about 20 meters (65 feet) from the pier.
"She was still out in the water lying on her back in a floating position because she told us later that she couldn't swim," Senior Constable Dean Kelly of the state water police told the Australian Broadcasting Corp. "She still had her mobile phone in her hand and initially she apologized and said sorry."
The woman was taken to a hospital for treatment. Police said she is a foreigner, but declined to say from which country.
"With Facebook, or social media in general as far as we're concerned, if you're anywhere near the water just pay attention," Kelly said. "Especially if you can't swim."