It depends. Some federal jobs require a college degree with a certain major field of study or specific academic courses at the baccalaureate or graduate level, while others will accept a degree in any field or don't require a college degree at all.
Jobs requiring a college or graduate level degree in a specific field of study
These jobs tend to involve research, scientific, or professional work (such as a specialist in contracts, medicine, engineering, biology, psychology, or accounting). To qualify, you must have completed all college or graduate level courses at an accredited (or with pre-accredited status) college recognized by the Secretary of the U.S. Department of Education.
Jobs requiring any college level degree
Many federal jobs will accept a baccalaureate degree in any field. Job applicants usually enter these jobs at the entry grade levels (typically GS-05 or GS-07 grade levels or equivalent) and acquire on-the-job training and work experience before advancing to higher grade levels. These jobs are sometimes advertised as “trainee,” “intern,” or “student program” positions. The hiring agency can answer questions about eligibility and your education.
What if I don't have a college degree?
If you've been in the job market for a while and have accumulated an extensive work history, you may be well qualified for many jobs even without a college degree. Except for certain professional and scientific positions, a college education may not be necessary. You can qualify for many federal jobs based on job-related work experience.
If you're just starting out, you can qualify for jobs at the GS-2 level with just a high school diploma. You can also qualify for most clerical and assistant positions with as little as 3 months of general work experience. “General experience” is work experience that's not directly related to the job but demonstrates the ability to acquire the particular knowledge, skills, and abilities to perform the work of the job.
You'll need additional work experience to qualify for jobs at a higher grade (or equivalent) level. Jobs starting at the GS-5 grade (or equivalent) level require one year of specialized experience equal to the next lower grade. “Specialized experience” is work experience that's directly related to the job which you are applying. For example, to qualify for a GS-6 grade (or equivalent) level, you must have a minimum of one year of specialized experience equivalent to a GS-5 grade (or equivalent) level.