How do you say I don't like it because in french?

"I don't like it" is "Je ne l'aime pas." If your reason is a separate sentence, use "parce que". E.g. "I don't like it (the food) because it is rotten." "Je ne l'aime pas parce qu'il est pourri." But if your reason is a noun, use "à cause de" E.g. "I don't like it because of my allergy." "Je ne l'aime pas à cause de ma allergie."