The person is a moral and legal concept that refers to a living agent, who can be held accountable for his or her actions. This means that persons cannot be understood as entities that are purely causally affected, resulting in various mental phenomena. The phenomena studied by psychology do not simply “happen”—like apples falling from trees due to the effect of gravity—but must be seen as “being done” by active, forward-looking persons with intentions. This gives psychologists a reason to construct their discipline based on a notion of personhood. In this entry, the conceptual history of personhood is unfolded followed by a discussion of challenges to the received notion of personhood. Finally, suggestions for how to think about personhood are articulated that leave room for both normative and causal perspectives in psychology.