It is generally not recommended that 9th graders take AP classes. This is because AP classes have a rigorous university-level curriculum that students new to high school and in the 9th grade may not be prepared for. Certain AP subjects, such as European History and World History, are excellent choices for 10th graders, but most AP classes are best suited to high school juniors and seniors. But if you’re up for a challenge, there is no harm in trying!