It depends. If you want to be an actor, it's very helpful when you've taken a bunch of stuff having to do with drama. If you take a lot of theatre/acting classes, you'll be more likely to be cast in plays, which go down on the resume you send to theatre companies.
I have a few friends who are aspiring actors and they're all majoring in theatre and are also taking speech, voice, and dance classes. You could major in theatre (not only musical theatre workshops and stuff like that, but the history behind plays/playwrights, etc) and then have a certificate for speech and gain experience in singing/voice inflection and movement on stage.
There are so many options open to you! I would suggest you see a counselor about all of this, and good luck!