Confirms last month's rumours of a swoop for the facial recognition start-up.
Facebook has been hard at work recently, making acquisitions to strengthen its core business, with Instagram's $1 billion nab still the most pricey.
Now, it has finalised its move for facial recognition tech provider Face.com.
Observers believe the solution will be used to improve Facebook's much criticised mobile operation.
Gil Hirsch, CEO of Face.com, said: "We love building products, and like our friends at Facebook, we think that mobile is a critical part of people’s lives as they both create and consume content, and share contentwith their social graph.
"By working with Facebook directly, and joining their team, we’ll have more opportunities to build amazing products that will be employed by consumers – that’s all we’ve ever wanted to do."
He also said that Face.com would continue to support the developer community that uses its tech across a number of apps, providing regular blog updates and newsletters.