The TV drama follows the adventures of Caitriona Balfe's character Claire, a British former World War II combat nurse, who is magically transported through an ancient stone circle to 18th century Scotland.
Sam Heughan plays Jamie, the lion-hearted Scottish warrior with whom she falls in love while trying to make her way back to modern day and her academic husband Frank, played by Tobias Menzies. Menzies also plays Frank's evil ancestor and the British army officer of whom the time-transplanted Claire runs afoul.
Season 2 will be at least 13 episodes and will be based on Dragonfly in Amber, the second of eight books in author Diana Gabaldon's Outlander series.
"The overwhelming support Outlander has received from the fans, viewers and critics made the decision for us to go ahead with the second book a very easy one. Diana Gabaldon has given us years of great drama," Starz Chief Executive Officer Chris Albrecht said in a statement Friday.
"With an incredible artist such as Ronald D. Moore at the helm and a cast as spectacular as this, we look forward to continuing this spell-binding journey with Claire, Jamie, Frank, Brianna, Roger and everybody over the centuries."
"I'm thrilled at the prospect of doing another season of this show for Starz. This project has been a labor of love from the very beginning and it's incredibly gratifying to see it succeed with viewers and critics alike," Moore said.
"Fans of the Outlander books have waited a long time to see this incredible story brought to life on screen, and Ron and his team have delivered a show that exceeds expectations," said Zack Van Amburg, president of programming for Sony Pictures Television, which produces the show. "We look forward to our continued partnership with Starz to present the next chapter of this epic tale to longtime fans and viewers who are just discovering the series."