This Article presents a framework for analyzing searches of privately-owned and employer-owned cell phones by both public and private employers. For employee-owned cell phones, this Article argues that such devices are entitled to the greatest constitutional protection under relevant Fourth Amendment precedent, including Riley v. California, and are typically beyond the reach of the Fourth Amendment’s workplace exception, making them generally immune from search by public employers. Given the highly offensive nature of personal cell phone searches, this Article further argues that private employers would typically face liability in tort for most personal cell phone searches. Nevertheless, for both types of employers, this Article contends that limited searches of personal cell phones might be permissible if an employer has implemented a clear and narrow policy authorizing such searches, to which employees have voluntarily consented, that is itself justified by a legitimate business need to manage or review particular employment-related data contained within the phone. For employer-owned cell phones, this Article recognizes that employees often cannot expect privacy in such devices vis-a-vis their employers, particularly where an employer’s policy permits their inspection, making them more freely searchable by employers. Nevertheless, in cases where an employee could reasonably expect privacy in an employer-issued cell phone, as in certain instances where the employee is the exclusive user of the device, this Article argues that employers should conduct such searches in a reasonable manner. Accordingly, for either public or private employers, this Article argues that when an employer wishes to search an employer-issued device, the employer should ensure it has a strong business justification for the search, should limit its search to avoid accessing private information unrelated to the intrusion’s justifications, and should select the least intrusive means available for conducting the search. In the end, determining whether an employer may lawfully search or seize the contents of an employee’s cell phone must be done on a case-by-case basis. However, the principles identified in this Article will serve as helpful guides for employers and reviewing courts in specific cases.