Os Guinness is an author and social critic. Os has written or edited thirty books on a wide range of themes, including The American Hour, Time for Truth, The Call, Invitation to the Classics, Long Journey Home, Unspeakable, A Case for Civility, and A Free People's Suicide: Sustainable Freedom and the American Future, published by InterVarsity Press in August, 2012. 

Previously, Os was a freelance reporter with the BBC. Since coming to the United States in 1984, he has been a Guest Scholar at the Woodrow Wilson Center for International Studies and a Guest Scholar and Visiting Fellow at the Brookings Institution. From 1986 to 1989, Os served as Executive Director of The Williamsburg Charter Foundation, a bicentennial celebration of the First Amendment. In this position he helped to draft The Williamsburg Charter which was signed by former presidents Jimmy Carter and Gerald Ford, Chief Justices William Rehnquist and Warren Burger, Coretta Scott King, Elie Wiesel, several Members of Congress, and many others. 

Os also co-authored the public school curriculum, Living With Our Deepest Differences. In 1991, Os founded the Trinity Forum, and was Senior Fellow there until 2004, conducting seminars for leaders around the world and publishing seven major curricula, such as Entrepreneurs of Life, When No One Sees, Steering through Chaos, the Great Experiment and Doing Well, Doing Good. Os has been a frequent speaker and seminar leader at political and business conferences in both Europe and the United States (including “TED”). Os has also been Senior Fellow at the EastWest Institute in New York, where he drafted Charter for Religious Freedom, a reaffirmation of Article 18 of The Universal Declaration of Human Rights that was published in Brussels at the European Parliament in 2012 with the endorsement and support of the United Nations Rapporteur on Religious Freedom. Os lives with his wife Jenny in McLean, Virginia, and they have one adult son.