XM Satellite Radio (XM) is one of two satellite radio (SDARS) services in the United States and Canada, operated by Sirius XM Radio. It provides pay-for-service radio, analogous to cable television. Its service includes 73 different music channels, 39 news, sports, talk and entertainment channels, 21 regional traffic and weather channels and 23 play-by-play sports channels. XM channels are identified by Arbitron with the label "XM" (e.g. "XM32").

The company has its origins in the 1988 formation of the American Mobile Satellite Corporation (AMSC), a consortium of several organizations originally dedicated to satellite broadcasting of telephone, fax, and data signals. In 1992, AMSC established a unit called the American Mobile Radio Corporation dedicated to developing a satellite-based digital radio service; this was spun off as XM Satellite Radio Holdings, Inc. in 1999. The satellite service was set to officially launch on September 12, 2001, however, due to the September 11 attacks, the decision was made to postpone the official launch date to September 25, 2001.

Satellite radio is an analogue or digital radio signal that is relayed through one or more satellites and thus can be received in a much wider geographical area than terrestrial FM radio stations. While in Europe many primarily-FM radio stations provide an additional unencrypted satellite feed, there are also subscription based digital packages of numerous channels that do not broadcast terrestrially, notably in the US. In Europe, FM radio is used by many suppliers that use a network of several local FM repeaters to broadcast a single programme to a large area, usually a whole nation. Many of those have an additional satellite signal that can be heard in many parts of the continent. In contrast, US terrestrial stations are always local and each of them has a unique programme, albeit they are sometimes interconnected for syndicated contents; but each local station still carries its own commercial and news breaks even then. This means that a national distribution of the contents of original terrestrial stations via satellite makes no real sense in the US, wherefore satellite radio is used in a different way there. History: Began broadcasting January 5, 2001 at 11:17AM Eastern, Tim McGraw was the first artist ever played on satellite radio. He gave a special welcome introduction which segued into his song "Things Change" on Sirius! Mobile services, such as Sirius, XM, and Worldspace, allow listeners to roam across an entire continent, listening to the same audio programming anywhere they go. Other services, such as Music Choice or Muzak's satellite-delivered content, require a fixed-location receiver and a dish antenna. In all cases, the antenna must have a clear view to the satellites. In areas where tall buildings, bridges, or even parking garages obscure the signal, repeaters can be placed to make the signal available to listeners.