Merak (Beta Ursae Majoris) is a star in the constellation of Ursa Major. It is more familiar to northern hemisphere observers as one of the "pointer stars" in the Big Dipper, and a line connecting it with nearby Alpha Ursae Majoris (Dubhe) extends to Polaris, the north star. It is also one of the five stars in the Big Dipper asterism that form a part of a loose open cluster called the Ursa Major moving group, sharing the same area of space and not just the same patch of sky by our perspective. The name is derived from the Arabic maraqq "loins" (of the bear).

In Star Trek, Merak II was a planet in the star system which was home to a Federation population in the 23rd century. In 2269 the planet experienced a bacterial botanical plague. The plague was treated with a toxic ore, known as zenite, which was acquired by the USS Enterprise. (TOS: "The Cloud Minders"). In 2370, Quark claimed that Elim Garak had ordered a sizing scanner from Merak II from the Ferengi. (DS9: "The Wire")

In reality, Merak is fairly typical for a main sequence star of its type, although being slightly hotter and larger than our own Sun, it shines several times brighter than our home star. It is distinguished in the fact that evidence shows the star is surrounded by a cooling disk of dust, much like those discovered around Fomalhaut and most notably Vega. No planets have been discovered orbiting Merak, but the presence of the dust indicates they may exist or be in the process of forming.