The 28-year-old, whose contract at the Championship club was set to expire this summer, has now committed to the Cardiff City Stadium until 2019.
Ecuele Manga joined the Bluebirds from French side Lorient for £5m in 2014 and has since featured 77 times, scoring five goals.
"I am really pleased to be continuing my adventure with this magnificent club," Ecuele Manga told the Cardiff website. "I would like to thank the manager and the board for having trust in me. Now it's time to work towards getting back to where we all want to be."
Cardiff manager Neil Warnock added: "It's been quite a long process to get this one done, but what's been clear to me throughout it all is that Bruno wants to play for this club, which is the most important thing. I'm absolutely delighted."
Ecuele Manga was named as Cardiff's player of the season during the 2014-15 campaign.