Marketing
Public Relations
Business
Hospitality/Hotel Management
Communication

Unfortunately, event planning is not a licesned profession so just about anyone can do it. When your in school, some things that will help you further pursue a career in this field would be:

1) Join PRSSA.
2) Get a job working with a catering company. Try to work yourself up to a lead or manager because this will give you the skills needed to plan a food budget and also work with caterers.
3) Find out which organization on your campus plans the student activities and join. This will give you great experience.
4) Do as many internships as you can. You will get to workin the field and hopefuly narrow down what type of events you wish to plan or work in.

Once you get a few years experience in the field, you can become a Certified Meeting Planner by taking a test. If you are working with convention centers or large venues, this is a highly viewed certification. It can be difficult to get and also expensive if you have to take the test more than once but it is worth it.

The event field is hectic and hard. The hours are irregular and your job is often thankless. There are always problems you wouldn’t ever think of. It is also the best job in the entire world.
References :
I’ve been working in the event field for 5 years, doing everything from serving at a small party to planning a 300k+ person event. I’ve worked with Fortune 500 companies as well as part-time teachers who plan festivals for their 600 person community.