OSP or Osp may refer to:
Places Osp, a valley and a village in Slovenia
Biology Outer surface proteins (Osp), expressed in the outer membrane of some gram-negative bacteria, particularly Borrelia burgdorferi
Organizations Oblate Sisters of Providence, a Roman Catholic women's religious institute Office of Special Plans, a U.S. intelligence unit (2002–2003) Onafhankelijke Socialistische Partij (Independent Socialist Party), a revolutionary socialist political party in the Netherlands Orchestra of St Paul's, a professional chamber orchestra resident at the Actors' Church, London Oregon Star Party, an annual event in the United States for observational astronomy Oregon State Police, an American law enforcement agency
Technology Online service provider, a supplier of internet content Open Settlement Protocol, a standard for ISPs to exchange information on IP telephony Open Source Physics, a project to encourage open source code libraries for numerical simulation Open Specification Promise, a legal statement concerning use of Microsoft intellectual property Open Syllabus Project, an open-source syllabus database OpenShot, a free and open-source video editor for Windows, macOS, Linux, and ChromeOS Operating System Projects, an environment for teaching about computer systems Orbital Space Plane, a NASA concept to support the International Space Station Organic solderability preservative, a method for coating printed circuit boards Outside plant, the telecommunications or electrical cabling between supplier and customer
Other Ovince St. Preux, an American martial artist known as OSP Orthosymplectic group