Legitimated authorities enjoy approval, support, and compliance from subordinates. Thus, legitimacy enhances authorities’ effectiveness across broad arenas, such as the judiciary, law enforcement, and the workplace. Understanding what shapes subordinates’ personal view of an authority as legitimate (propriety) elucidates how authorities can gain propriety. We investigate the relative impact of instrumental, relational, and moral bases of legitimacy on subordinates’ assessments of their workplace authorities’ propriety. We additionally consider social influences (i.e., “what others think”) captured by perceived collective support for the authority from superiors (authorization) and peers (endorsement). Results from a survey of 2,062 US workers indicate that all individual bases, as well as support by superiors and peers, positively contribute to propriety. Among the individual bases, instrumental concerns are most impactful, and the effect of endorsement far exceeds that of authorization. In an exploratory analysis, we show that perceptions of collective support moderate the effects of some of the individual bases of propriety. Our study reveals that it is not only how an authority behaves toward subordinates but also “what others think” that influences propriety.