Is I want to invite you all correct English?

"I want to invite you all" is grammatically correct, but it sounds a bit awkward. Here are some better ways to say it:

* "I'd like to invite you all..." (More polite and formal)

* "I want to invite everyone..." (More direct and casual)

* "I'd love to invite you all..." (More enthusiastic)

The best choice depends on the context and your relationship with the people you are inviting.