Traditionally, Christians would eat pancakes on the last day before Lent begins, to use up foods like eggs and milk, before starting 40 days of fasting for lent.
Now, Pancake Day is celebrated by people all over the world, and some people even hold pancake-flipping competitions.
If you want to join in, you could try this basic pancake recipe, adapted from celeb chef Delia Smith, to make enough mixture for 12-14 pancakes. Yum!
But don't forget to ask your mum and dad to help!
Sift the flour and salt into a large mixing bowl.
Make a well in the centre of the flour and break the eggs into it.
Begin whisking the eggs.
Gradually add small quantities of the milk and water mixture, still whisking.
Whisk until all the liquid has been added and the batter has the consistency of thin cream.
Melt the butter in a pan.
Spoon 2 tbsp of it into the batter and whisk it in. Use the rest of the butter to grease the frying pan before you make each pancake.
Get the pan really hot, then turn the heat down to medium - be really careful doing this bit. You might want to get your mum and dad to help at this point!
Ladle 2 tbsp of the batter into the hot pan all in one go.
Tip it around from side to side to get the base evenly coated with batter.
After about half a minute, and when the bottom is golden in colour, flip the pancake over.
The other side will only need a few seconds to cook.
Slide the pancake out of the pan onto a plate.
To serve, sprinkle each pancake with freshly squeezed lemon juice and caster sugar.
Enjoy!
On Shrove Tuesday, people will be tucking into a pancake feast, as part of a tradition that has lasted for centuries.