Mark Steyn (; born December 8, 1959) is a Canadian conservative author and commentator. He has written several books, including the New York Times bestsellers America Alone: The End of the World As We Know It and After America: Get Ready for Armageddon. He has guest-hosted the nationally syndicated Rush Limbaugh Show, as well as the Tucker Carlson Tonight on Fox News, on which he regularly appears as a guest.