St Davids Day is celebrated annually on the 1st of March. People who live in Wales and who are of Welsh origin celebrate their Patron Saint - St David.
People celebrate by wearing traditional costume, parades and wearing daffodils and leeks.
The flag of St David is black with a yellow cross and will be flown more than usual on the day along with the Welsh Flag.
During a battle against the Saxons St David told his men to wear a leek so they were able to distinguish who the enemy was. They went on to win the so the leek has become a Welsh symbol.