Q: Can I apply for OCS if I am not in college?
A: The short answer is, “no”. A requirement of any Marine commissioning program is that you be currently enrolled in college full-time (credit load depending on your educational institution.) Or, have a 4 year degree from a accredited institution. So you can apply for and attend OCS after college.
The major itself does not matter to the Marine Corps. And unlike service branches like the Navy or Air Force, it has no bearing on your selection.
Your OSO can start an application for you before you are enrolled in college, or during your first semester. However, many won’t because you don’t have a GPA yet. OSOs are extremely busy people and they won’t spend much time on a applicant who doesn’t meet the basic requirements.
For that matter, some OSOs may allow you to start an application if you are enrolled in community college, with the intent to transfer to a baccalaureate (i.e. 4 year) granting institution. However, you are not eligible to have your package briefed to a selection board until you are enrolled somewhere that can grant you a bachelors degree.