The Space Telescope Science Institute (STScI) is the science operations center for the Hubble Space Telescope (HST; in orbit since 1990) and for the James Webb Space Telescope (JWST; scheduled to be launched in 2013). STScI is located on the Johns Hopkins University Homewood campus in Baltimore, Maryland and was established in 1981 as a community-based science center that is operated for NASA by the Association of Universities for Research in Astronomy (AURA). Today, in addition to performing continuing science operations of HST and preparing for scientific exploration with JWST, STScI manages and operates the Multi-mission Archive at Space Telescope (MAST), the Data Management Center for the Kepler mission and a number of other activities benefiting from its expertise in and infrastructure for supporting the operations of space-based astronomical observatories. The staff at STScI consists of scientists (mostly astronomers and astrophysicists), software engineers, data management and telescope operations personnel, education and public outreach experts, and administrative and business support personnel. There are approximately 100 Ph.D. scientists working at STScI, 15 of which are ESA staff who are on assignment to the HST project. The total STScI staff consists of about 350 people. STScI operates its missions on behalf of NASA, the worldwide astronomy community, and the general public. The science operations activities directly serve the astronomy community, primarily in the form of HST (and eventually JWST) observations and grants, but also include distributing data from other NASA missions (e.g., Far Ultraviolet Spectroscopic Explorer, Galaxy Evolution Explorer) and ground-based sky surveys. The ground system development activities create and maintain the software systems needed to provide these services to the astronomy community. STScI's public outreach activities provide a wide range of information, on-line media, and programs for formal educators, planetariums and science museums, and the general public. STScI's award-winning public outreach websites receive millions of hits per month. STScI also serves as a source of guidance to NASA on a range of optical and UV space astrophysics issues. The STScI staff interacts and communicates with the professional astronomy community through a number of channels, including participation at the bi-annual meetings of the American Astronomical Society, publication of quarterly STScI newsletters and the STScI website, hosting user committees and science working groups, and holding several scientific and technical symposia and workshops each year. These activities enable STScI to disseminate information to the telescope user community as well as enabling the STScI staff to maximize the scientific productivity of the facilities they operate by responding to the needs of the community and of NASA.