Online self-disclosure has been studied in a variety of disciplines for more than two decades. Self-disclosure is any information about the self communicated to another person; it is generally decomposed into five dimensions: amount, depth or intimacy, honesty and accuracy, polarity, and intent. In this dissertation, we offer a new contextualization of self-disclosure to online settings. While our review of the literature suggests four dimensions are conceptually similar across contexts, the fifth – intent – is problematic. Intent refers to the willingness to share personal information. In the online context, intent items direct attention to whether one intends to post or is unaware they are posting certain information. In the offline context, unintentional or accidental disclosures occur mostly due to environmental (i.e. seeing a colleague in a locker room) or nonverbal (i.e. facial expressions) cues. However, online communication differs from offline communication in four ways: reduced nonverbal cues, asynchronicity, editability, and breadth of audience. The first three of these unique attributes imply online intent is fundamentally different from offline intent. To account for these differences, there is a need to contextualize self-disclosure to the online environment. We accomplish the contextualization of online self-disclosure through two essays. In essay one, we conduct a thorough review of the literature to evaluate the contextualization of the measures of online self-disclosure and identify areas for improving the construct’s measurement. Based on the analysis, we propose four context-specific dimensions to supplant intent in the decomposition of online self-disclosure: willingness to participate, reciprocity, audience control, and conscientious use. In essay two, we develop an operational long- and short-form measure and subject it to rigorous validity testing; in doing so, we compare the new measure to two established instruments and examine its performance within a nomological model. We find support for two of the proposed dimensions and for a new structural definition of online self-disclosure involving two intermediate latent variables: message and behavior. This new structure could help improve the content validity of short, simple instruments that are frequently seen in the literature.