Rumours of this deal, which comes just weeks after Facebook bought photo app Instagram for $1bn, have been circulating since last month.
The companies did not specify plans for the partnership, but Face.com hinted in a blogpost that it could be working with the social network on its mobile features.
Facebook shares jumped five per cent to $31.49 on news it had bought the Tel Aviv-based startup, which already has two apps on Facebook.
Meanwhile Facebook yesterday unveiled its official Olympic page, which will allow athletes to communicate with fans and provide personal updates from the Games.
But the page will not carry any advertising due to the “clean venue” rules which stipulate that the Olympic stadia should remain free of brands and marketing.