The Office has issued a notice of allowance to the social networking juggernaut, allowing the company to own the word after paying a fee, the NY Post reported.
The trademark will allow Facebook to challenge any of the 89,000 websites using the word "face" in their domain name.
The trademark would cover "telecommunication services, namely providing online chat rooms and electronic bulletin boards for transmission of messages among computer users in the field of general interest and concerning social and entertainment subject matter, none primarily featuring or relating to motoring or to cars".
A Facebook spokesperson would not reveal why an exemption was given to cars.
Several companies are considered to be in the sights of Facebook’s legal department, including Apple over its video conferencing service Facetime and a pornography website called Faceporn.
Facebook has also sued websites Teachbook, Placebook and Lamebook in order to protect the social network’s identity.
Facebook has already been successful in trademarking the words "Like" and "Wall".