National Trivia Day icon. Today is National Trivia Day, and what better way to celebrate than by learning a few fun facts about this widely celebrated day? National Trivia Day is the perfect opportunity to showcase your knowledge and flex your brain muscles. This day has been celebrated all around the world since its inception in 2008. A variety of activities are usually associated with National Trivia Day, ranging from throwing trivia parties to creating quizzes for friends and family.