When Is National Pi Day 2025 Celebration. Pi day 2024 celebration unlike pie, which has the same pronunciation but is written differently, pi has a completely distinct meaning. The beautiful constant pi (π) is celebrated by mathematicians around the world on national pi day on march 14.

Check also the date of pi day in 2025 and in the following years. Just up ahead, check out more about pi day deals plus fun facts on pi with related resouces on ways to celebrate national pi day.