Australian Prime Minister Scott Morrison confirmed during a session in parliament on Thursday that Sigley, who ran a tour company and was studying for a master's degree in Korean Literature at Pyongyang's Kim Il Sung University, had been freed.
"We were advised that the DPRK have released him from detention and he has safely left the country and I can confirm that he has arrived safely," Morrison said, using the official name for North Korea, the Democratic People's Republic of Korea.
The release came after a meeting with Swedish embassy officials and the North Korean government in Pyongyang. Australia does not have a diplomatic presence in North Korea.
"On behalf of the Australian government I would like to extend my deepest gratitude to the Swedish authorities for their invaluable assistance in securing Alek's prompt release, which demonstrates the value of discreet behind-the-scenes work by officials in solving sensitive consular cases in close partnership with other governments," Morrison said.
In video footage of his arrival at Beijing Airport, a smiling Sigley told reporters that he was feeling "great."
"I'm OK, I'm OK, I'm good, I'm very good," he said, but didn't answer any questions about his detention.
The 29-year-old's father told media in Perth that he was "over the moon" that his son had been released.
"Of course the last week has been a difficult week not having any information, we're just so happy that the situation has been resolved," Gary Sigley said.
"I also know that he's been in good spirits and he's been looked after the whole time."
Sigley is expected to continue on to Tokyo, Japan, from Beijing.
Concerns about Sigley were raised when his family lost contact with him early last week and his normally active social media accounts went silent.
Sigley kept a blog for his tour company, Tongil Tours, which offered tours of North Korea to foreigners. He also contributed articles about life in North Korea to outlets including The Guardian and NK News, which first reported his release.
He speaks fluent Korean and was one of the few foreigners living in Pyongyang.
It is still unclear why he was detained.