It's a global celebration of Irish culture. It Particularly remembers St Patrick's, one of Ireland's patron saints, who ministered Christianity in Ireland during the fifth century.
Every 17th of March, Ireland celebrates one of its patron saints, St Patrick, with a traditional feast.
Singing , dancing , a parade and a pint or two - the Irish known how to party and celebrate this day.
Watch St Patrick's Day performances by West End stars, Irish acts and community choirs, plus a huge caili on the Trafalgar Square stage, hosted by Irish stand-up comedian Jarlath Regan. Then tuck into traditional and modern Irish food from the market, and enjoy special family activities for free.