The Fermi Gamma-ray Space Telescope is a probe-class international and multi-agency observatory launched in 2008 that surveys the dynamic gamma-ray sky across energies from about 8 keV to over 300 GeV. Equipped with the Large Area Telescope and the Gamma-ray Burst Monitor, Fermi delivers rapid all-sky coverage roughly every three hours while retaining the ability to point at specific targets. Its science program includes mapping the gamma-ray sky and its background, investigating blazars and other active galactic nuclei, studying pulsars, tracking gamma-ray bursts, exploring the nature of dark matter, and examining particle acceleration in novae. As the successor to the Compton Gamma-ray Observatory from NASA's Great Observatories program, Fermi has operated with high reliability and no significant performance degradation, has no mission-limiting consumables, and makes its data immediately and publicly available to enable a broad range of astrophysical research.