The word 'apple' has a long history! It comes from the Old English word 'æppel,' which is similar to words in other languages like 'apel' in German and 'pomme' in French (which actually means 'fruit').
A long time ago, people needed to name the delicious fruit that grows on trees, and they chose a word that sounded nice to them. It's a bit like how you name your toys or pets — they need names so you can talk about them!
So, no single person named the apple. Instead, many people over many years agreed that 'æppel' was a good name for this tasty fruit, and that's how we got the word 'apple' that we use today!