How do you say it will be fun in french?

Ce sera amusant.

Here's a breakdown:

* Ce - this/it

* sera - will be

* amusant - fun

You can also say:

* Ça va être amusant. (This will be fun.)

* On va s'amuser. (We're going to have fun.)

The best choice depends on the context and what you want to emphasize.