An underclassmen, in standard four year American high schools and colleges, is either a sophomore or freshmen, and in cases with more then 4 grades, any grade level before freshmen (ie. combined junior high and high schools). Rarely, a sophomore can be considered an upperclassmen, usually in a school with more than four grades, but is not usually considered as such.

Underclassmen are often treated more strictly by school systems in efforts to help them become part of a school community. Freshmen and sophomores are often given their own athletic teams as well, giving those students who are unable to participate on a varsity level a chance to improve their skills for following years. Underclassmen however are not normally strictly limited to freshmen and JV levels, assuming they posses the skill to compete on the varsity level.