Mother's Day is a special day honouring mothers and it's celebrated in loads of countries throughout the world - but in Britain it's also known as Mothering Sunday.
History of Mother's Day
During the Middle Ages the custom developed of allowing people who had moved away from where they grew up to come back and visit their home churches, and their mothers, on the fourth Sunday of the Christian festival of Lent.
This became Mothering Sunday in Britain. As the dates of Lent vary each year, so does the date of Mothering Sunday.
Although it's often called Mother's Day in the UK, it has no connection with the American Mother's Day.
Mother's Day in the US
In the United States, Mother's Day is celebrated on the second Sunday of May each year.
The idea started in America when a woman called Anna Jarvis held a small memorial service for her own mother on May 12, 1907.
Soon most places in America were observing the day and in 1914 the US president made it a national holiday, celebrated on the second Sunday of May.
Lots of other countries celebrate Mother's Day at different times of the year as well.
The food item traditionally associated with Mothering Sunday is Simnel cake - a type of fruit cake. These days, Simnel cakes are more usually linked with Easter.
But flowers and chocolates are probably more popular still!