St. Patrick's Day this year is Saturday, March 17.
All around the world, people of Irish descent celebrate their culture and heritage with parades and parties.
Places from Montserrat to Singapore celebrate St. Patrick's Day in their own unique ways.
St. Patrick's Day, which commemorates the arrival of Christianity in Ireland, gives millions of people of Irish descent a reason to celebrate their culture and heritage, and is marked by massive parades and raucous parties.
Even countries without prominent Irish populations take part in the festivities. According to historians Mike Cronin and Daryl Adair, St. Patrick's Day is celebrated in more countries than any other national festival.
See photos of St. Patrick's Day celebrations from around the world: