Our relations with other animals are ubiquitous in human life, yet the psychological structure of our connection with animals is just beginning to receive empirical attention. Drawing on theories of social identification and intergroup relations, we investigate the various ways that people identify with animals. Across 7 studies, we introduce the Identification with Animals Measure (IWAM) and uncover 3 dimensions by which humans identify with animals as a group: solidarity with animals, animal pride, and human-animal similarity. First, we establish the reliability, factorial structure, and predictive validity of the 3-factor IWAM. Next, we find that these factors predict a distinct set of attitudes and behaviors toward animals. Solidarity with animals is defined by feeling connected to other animals and is associated with more contact with animals (i.e., pets) and a greater desire to help animals and to engage in collective actions on their behalf, even if this implies withdrawing privileges to humans. Human-animal similarity is defined by the perception that animals share similarities with humans; this dimension is associated with increased moral concern for their welfare and a greater attribution of typically human traits to other animals. Finally, animal pride is defined by a direct recognition and positive endorsement of the social category that includes all animals, and is associated with viewing humans as more animal-like, and with more competitive and instrumental intergroup relations. The findings confirm that identification with animals is a multidimensional construct that is colored by the unique and complex nature of our relations with nonhuman animals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).