Facebook has rolled out the feature in UK, US, Canada, India and Australia and the system works via an algorithm that identifies what topics have had a sharp increase in popularity, as opposed to overall volume for a subject.
Chris Struhar, engineering manager at Facebook, said: "Facebook is a space where people from all over the world gather every day to share their thoughts and participate in real-time conversations, from the highlights of the Golden Globes to the passing of Nelson Mandela.
"Trending [is] a new product that's designed to surface interesting and relevant conversations in order to help you discover the best content from all across Facebook."
The trending feature appears to the right of the user’s News Feed and Facebook adds the list is "personalised" because it also includes topics based on the user’s interests.
Topics are accompanied by a headline that summarises why the topic is trending and the user can click on the headline to see the "most interesting" posts from friends or pages that are talking about the topic.
Struhar said Facebook will also test the trending feature on mobile and added there will be "continuous improvements over time".
The trending feed will also include posts from news organisations and celebrities, while posts from friends or pages users are following will rank higher in the feed.