Pen (disambiguation)

Pen can be:

• pen, the writing tool
• International PEN, a membership association of prominent literary writers and editors.
• The term used for the much-reduced and entirely internal shell of some cephalopod mollusks, especially squid.
• An enclosed location; for example, such as a pigpen.
• A short form of penitentiary.
• Sea pens, marine cnidarians of the order Pennatulacea.