"The rapid pace of our growth is humbling and exciting for us," the Telegraph quoted him, as saying.
"As of today, 250 million people are using Facebook to stay updated on what's happening around them and share with the people in their lives," Zuckerberg said in the Wednesday, Jul 15 blog post.
"As we celebrate our 250 millionth user, we are also continuing to develop Facebook to serve as many people in the world in the most effective way possible. This means reaching out to everyone across the world," he added.
Founded in California in 2004, Facebook has become the most popular online social networking service, eclipsing News Corporation-owned MySpace.