Stagecoach Manchester is a major bus operator in Greater Manchester, operating franchised Bee Network bus services on contract to Transport for Greater Manchester (TfGM).

Before deregulation in 1986, buses in the Greater Manchester area were publicly funded and operated under the name of Greater Manchester Transport. In 1986 Greater Manchester Transport became known as GM Buses, which was owned by the metropolitan borough and city councils of Greater Manchester, but were at arms' length from the local town halls.

In December 1993, GM Buses was split in two companies: GM Buses North and GM Buses South. It was planned that the two companies would compete against one another, however they operated without doing so through to their respective buyouts.

In April 1994, GM Buses South was sold in a management buyout for £16 million (equivalent to £33,760,000 in 2025). GM Buses South faced an uphill struggle as over 40 competitors were running on routes in and around central Manchester following deregulation, with the Bee Line Buzz Company, MTL Manchester, Finglands Coachways, Mayne and Walls being the operator's main competitor on the lucrative south Manchester routes.

In response to increasing competition by MTL, in 1994, GM Buses South set up Birkenhead & District in Liverpool, running Daimler Fleetlines in the blue and cream livery of the former Birkenhead Corporation. This new company operated in direction competition with MTL in the Wirral region until June 1995, when it was closed due to heavy competition rendering the company unprofitable.

Perth-based Stagecoach Holdings initially set up Stagecoach Manchester as a sub-brand of Ribble Motor Services subsidiary in January 1994 in order to compete on Manchester to Stockport route 192, directly undercutting GM Buses South's fares on the route by half price. Stagecoach marketed the operation as 'The Friendlier 192', claiming to beat all competitors along the route in terms of price and performance, and ran the route mainly using a new fleet of eighteen Alexander Dash bodied Volvo B6 midibuses based from a single depot in Bredbury.

Throughout 1994, GM Buses South bought a large number of secondhand buses, mainly Leyland Atlanteans and Leyland Nationals, while Stagecoach responded with more new buses in the shape of Alexander PS bodied Volvo B10Ms. In retaliation for competition on route 192, GM Buses South used its Charterplan coach fleet to compete with Stagecoach Ribble's route X43 to Burnley. By March 1995, however, competition between both operators ceased when Stagecoach agreed to no further competition on route 192, resulting in GM Buses South withdrawing services on the X43. Stagecoach Ribble loaned 20 redundant Alexander Dashes to GM Buses South the following April, and following an attempt to compete with GM Buses North in Salford, eventually sold Stagecoach Manchester, as well as 13 buses based at its Bredbury depot, to EYMS Group subsidiary Finglands Coachways in November 1995.

On 25 February 1996, GM Buses South was sold to Stagecoach for £40.7 million (equivalent to £81,694,000 in 2025), despite criticism from the Labour Party and protests from pensioners outside the Free Trade Hall. GM Buses South was rebranded as Stagecoach Manchester shortly after the sale, despite Stagecoach claiming that the GM Buses South brand would be retained, with new vehicles in the group's corporate livery delivered the following March. The existing Charterplan Travel coaching arm and commercial driver training company GMS Training remained unaffected by the rebranding, however Charterplan was later sold to the EYMS Group the following May, being integrated into the operator's East Yorkshire Travel coaching arm.