HD may refer to:
HDMI (High-Definition Multimedia Interface) is a proprietary audio/video interface for transmitting uncompressed video data and compressed or uncompressed digital audio data from a HDMI-compliant source device, such as a display controller, to a compatible computer monitor, video projector, digital television, or digital audio device.
HD Radio is a trademarked term for iBiquity's in-band on-channel (IBOC) digital radio technology used by AM and FM radio stations to transmit audio and data by using a digital signal embedded "on-frequency" immediately above and below a station's standard analog signal, providing the means to listen to the same program in either HD (digital radio with less noise) or as a standard broadcast (analog radio with standard sound quality).
HDFC Bank Limited is an Indian banking and financial services company headquartered in Mumbai, Maharashtra.
HD 209458 b (sometimes unofficially called Osiris) is an exoplanet that orbits the solar analog HD 209458 in the constellation Pegasus, some 150 light-years from the Solar System.
HD 189733 b is an extrasolar planet approximately 63 light-years away from the Solar System in the constellation of Vulpecula.
HD-MAC was a proposed broadcast television systems standard by the European Commission in 1986 (MAC standard), a part of Eureka 95 project.
HD 10180 is a Sun-like star in the southern constellation Hydrus that is notable for its large planetary system.