UMA or Uma may refer to:

• Uniform memory access, a computer memory architecture used in parallel computers
• Unlicensed Mobile Access, roaming between GSM and 802.11
• Upper memory area, a part of Extended Memory Specification in a PC
• Ursa Major, a constellation
• User-Managed Access, a protocol for delegated authorization based on OAuth
• Uma (genus), the genus name of the North American Fringe-toed lizards
• Cyclone Uma, a tropical cyclone which damaged Port Vila, Vanuatu, in 1987

Ursa Major (also known as the Great Bear) is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by Ptolemy (second century AD), it remains one of the 88 modern constellations. It can be visible throughout the year in most of the northern hemisphere. Its name, Latin for "the greater (or larger) she-bear", stands as a reference to and in direct contrast with Ursa Minor, "the smaller she-bear", with which it is frequently associated in mythology and amateur astronomy. The constellation's most recognizable asterism, a group of seven relatively bright stars commonly known as the "Big Dipper", "the Wagon" or "the Plough" (among others), both mimics the shape of the lesser bear (the "Little Dipper") and is commonly used as a navigational pointer towards the current northern pole star, Polaris in Ursa Minor. The Big Dipper and the constellation as a whole have mythological significance in numerous world cultures, usually as a symbol of the north.