The present research examined the impact of the expression of internal versus external control beliefs on attributions of humanness. Building on previous findings on the cultural norm of internality and the dehumanization of others in social perceptions, we hypothesized that, in a Western society, an individual’s expression of an internal locus of control (i.e., internality) results in a greater degree of humanization of that individual by others than an individual’s expression of an external locus of control (i.e., externality). Two studies examined the effect of a target’s expression of internality (vs. externality) on the attribution or denial of humanness to that target. We measured the targets’ degree of humanization via the mentalization of each target, assessed using the Mind Attribution Scale, and via attributions of uniquely vs. nonuniquely human characteristics (emotions in Study 1, traits in Study 2). Participants also judged the target’s likability. In line with our hypothesis, the target’s expression of internality (compared to externality) consistently resulted in the participants making stronger attributions of humanness to the target. In addition, covariance analyses showed that the participants ascribed more humanness to targets with an internal than with an external locus of control, independent of the target’s likability.