[Revised entry by David P. Schweikard and Hans Bernhard Schmid on December 9, 2020. Changes to: Main text, Bibliography] Collective intentionality is the power of minds to be jointly directed at objects, matters of fact, states of affairs, goals, or values. Collective intentionality comes in a variety of modes, including shared intention, joint attention, shared belief, collective acceptance, and collective emotion. Collective intentional attitudes permeate our everyday lives, for instance when two or more agents look after or raise a child, grieve the loss of a loved one, campaign for a political party, or cheer for a sports team. They are relevant for...