Public-Private Partnerships (P3s) are becoming an integral component of successful collaboration in 21st-century society. Predominately in western society, the private sector and government constantly distinguish themselves from each other while simultaneously collaborating to solve problems. Behind exploring partnerships pertinentto the security of the United States (US) lies not only with the benefit for the public sector, but also for the private sector. This thesis explores attributes of two successful P3s; the Federal Bureau of Investigation’s (FBI) InfraGard initiative and the State Department’s Overseas Security Advisory Council (OSAC). From inside and externally, InfraGard and OSAC represent some of the best examples of private and public citizens working together towards securing the safety of our nation. In a collaborative way, both initiatives have helped foster successful cross-sector partnerships between government agencies and private businesses in different ways partly due to laws, regulations, and protocols between companies, Nongovernment Organizations (NGOs), and other externalities outside the US Government (USG). Domestically, the FBI’s InfraGard can function as a NGO and easily work with government agencies and others under US law. InfraGard’s focus is largely on Critical Infrastructure Key Resources (CIKR) supporting the Homeland Security mission and protecting communities dependent on the private sector’s ownership and operation of these resources. In contrast, outside the US the relationships of USG departments and agencies, like the State Department and FBI, are different in almost every country, and require a very different P3 construct as exemplified by OSAC. OSAC is within the State Department and controlled by representatives from both sectors within each country council. Both initiatives have benefited significantly from technological advancements, particularly within communications. Information technology has spurred the shift from a largely amorphous society to a highly networked society dependent on the timely exchange of information. The Internet has strengthened globalization through near real-time connectivity. While supportive, this added to the complexity of P3s operating domestically, like InfraGard, as well as internationally, as with OSAC. Both serve as best practices in highlighting effective P3 models that government organizations and private-sector partnerships in support of our National Homeland Security efforts.