A system and a method for automatically populating chat recipients in an instant messaging system in which chat recipients are automatically populated from external data sources, e.g. clipboard, spreadsheet, document, database, directory, etc., and a chat session started with the click of a single user interface button or the like. A pop-up window is generated that allows the user to select a data source from which the chat recipients are to be obtained. The data source may be scanned to identify candidate names matching a predetermined name format, or the user is prompted to provide at least a portion of a search string. The user can then select which of the returned names are to be used in initiating the chat session. The disclosed system then generates a user interface object allowing the initiating user to perform an action with the selected recipients, including initiating a chat session.