In this article, we advance research on transparency by developing and validating a measure based on recent theoretical insights about its dimensionality. We find that transparency—defined as the perceived quality of information—is a three-dimensional construct consisting of perceived information disclosure, clarity, and accuracy. Evidence shows items associated with these dimensions can be aggregated into a single transparency construct. We also find that transparency (as an aggregate construct) is distinct from neighboring constructs such as informational justice and capable of predicting perceptions of the source’s trustworthiness (ability, benevolence, and integrity). Finally, we find evidence of measurement invariance between two commonly used referents of analysis, yielding confidence in the application of the proposed measure across research settings. We discuss implications of the new measure for research on transparency, the extension of the new measure to related research traditions, and the practical application of the new measure for managers interested in constructing and appraising transparent messages.