It's renowned for being the 'most romantic day of the year'.
And many of us use it as an opportunity to show affection for our loved ones with cards, flowers or chocolates.
But why exactly do we celebrate Valentine's Day and why does it fall on February 14?
Well we've trawled through the history books to find out the real reasons so you don't have to - and the background casts a very different light on the holiday.
Valentine's Day is an old tradition thought to have originated from a Roman Festival known as Lupercalia, according to History.com.
It was held on February 15 as a fertility festival dedicated to Faunus, the Roman god of agriculture.
During the celebrations boys would draw names of girls from a box and the pair would be partners during the festival.
These matches often led to marriage.
The festival survived the initial rise of Christianity but was outlawed at the end of the 5th century when Pope Gelasius declared February 14 St Valentine's Day.
13 And now these three remain: faith, hope and love. But the greatest of these is love.
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