Depending on the firm or the job, a proofreader might need a specific degree, or he may not. Some jobs will require English degrees or even journalism degrees. However, other employers only want to know about your skills and experience. If you are considering being a proofreader and you are going to college, appropriate degrees include those in the areas of writing, English, journalism, or proofreading, if your school has those degrees.
Other types of education that are just as important, and sometimes more important than schooling, include the education you've gotten at jobs and other experiences you have had. Experience in editing, proofreading, and writing is all very important. So are clubs and groups that have anything to do with journalism or editing, such as the school newspaper or yearbook committee.
The education that you've given yourself through the skills and abilities you already have is also very important to work as a proofreader. If you have been obsessed with grammar and correcting written mistakes, and if your friends and family often ask you to look over what they've written, you've already educated yourself in how to do the basic job of a proofreader. If you have these skills and abilities, you'll be more marketable as a proofreader and more likely to excel at it.
Your education in your work style and ethic is very important to your job. This education comes partially from your learning institution but also comes from within. If you have educated yourself to be hardworking and determined, you'll do well as a proofreader. If you have also learned how to sit still for long periods of time and focus on one project or problem, you're already on track to pursue an education to become a stellar proofreader.