Stagecoach Group, usually shortened to Stagecoach, is a British transport group based in Perth, Scotland. It operates buses and express coaches in the United Kingdom.

Stagecoach was originally founded in 1976 as Gloagtrotter, a recreational vehicle and minibus hire business. During the early 1980s, it took advantage of the deregulation of the British express coach market, launching services from Dundee to London using second-hand Neoplan coaches, competing against the then state-owned National Express Coaches and Scottish Citylink. Stagecoach purchased several recently privatised national bus groups from London Regional Transport, the National Bus Company, Scottish Bus Group and various city councils, as well as pursuing those that had opted for management buyouts and employee-owned corporations. During August 1996, Stagecoach acquired roughly one-third of all passenger rolling stock in the UK via the acquisition of the recently privatised leasing company Porterbrook; it sold the company on four years later. In 1997, Stagecoach was awarded the franchise to operate the recently privatised Sheffield Supertram system. In 1998, it purchased Prestwick Airport.

Following the sale of its London bus operations to Macquarie Bank in 2006, Stagecoach UK Bus concentrated on the bus market outside the UK capital. During 2007, Stagecoach was awarded the East Midlands franchise. In July 2007, it commenced operating the Manchester Metrolink tram network. During January 2009, Stagecoach purchased Preston Bus, a former rival in the Lancashire area, but was promptly compelled to sell it by the Competition Commission. In October 2010, it expanded further by re-acquiring East London and Selkent, Stagecoach's former London bus operations. During March 2015, Virgin Trains East Coast, in which Stagecoach held a 90% shareholding, commenced operating the InterCity East Coast franchise; the franchise was terminated early three years later as it was unable to fulfil the agreed payments.

During April 2019, private equity house Variant acquired Stagecoach's US division in exchange for $271 million. In April 2019, Stagecoach was disqualified from participating in three rail franchise competitions by the Department for Transport after it submitted non-compliant bids. During September 2021, it was reported that rival company National Express entered into talks to acquire Stagecoach. In May 2022, a rival takeover offer from a DWS managed investment fund bought Stagecoach.

The origins of Stagecoach Group can be traced back to 1976, at which point Ann Gloag and her husband Robin Gloag established a small recreational vehicle and minibus hire business called Gloagtrotter based in Perth, Scotland. Ann's brother, Brian Souter, an accountant, joined the firm and expanded the business into bus hire. In 1982, following the collapse of his marriage to Ann, Robin Gloag sold his ownership stake in the business and ceased any involvement. Around this time, the company would benefit greatly from the deregulation of the British express coach market in the early 1980s; specifically, the Transport Act 1980, which freed express services of 35 miles and over from regulation by the Traffic Commissioner, brought new opportunities for the company and services were launched from Dundee to London using second-hand Neoplan coaches. For a while, the company offered a very personal service with Brian Souter doing the driving and Ann Gloag preparing sandwiches and other snacks for the passengers.

Between 1981 and 1985, the company grew significantly, successfully competing against the then state-owned National Express Coaches and Scottish Citylink. Stagecoach entered local bus operation with the acquisition of McLennan of Spittalfield, near Perth. Its early success allowed Stagecoach to take advantage of the privatisation of the national bus groups. Several firms were purchased from London Regional Transport, the National Bus Company, Scottish Bus Group and various city councils. The company consolidated its operations during the 1990s by purchasing ex NBC and SBG bus companies that had been purchased via management buyouts and employee-owned corporations when privatised. In August 1989, Stagecoach withdrew from the long-distance express coach market, selling its operations to National Express, who rebranded the services as 'Caledonian Express'.

During the privatisation of British Rail, Porterbrook was formed as one of three rolling stock companies owning around a third of passenger railway locomotives, multiple units and coaching stock running on Network Rail's system which is leased to various train operators. Porterbrook was privatised via a management buyout before being purchased by Stagecoach for £825 million during August 1996. The acquisition garnered some public controversy and political criticism for the low value returned to the taxpayer. In April 2000, Stagecoach sold Porterbrook to the British banking group Abbey National in exchange for £1.44 billion.

In 1997, Stagecoach was awarded the franchise to operate the recently privatised Sheffield Supertram system, from the South Yorkshire Passenger Transport Executive, who owned the system. Stagecoach bought the remaining 27 years of a 30-year franchise in exchange for £1.15 million, which was substantially below the anticipated £80 million that the councils had hoped to raise to help pay off the accumulated debts to build the system. The franchise, which expired in March 2024, was operated under the Stagecoach Supertram brand, the company having responsibility for the operation and maintenance of the tram system. When Stagecoach took over the system, it was struggling, both financially and in terms of attracting passengers; patronage subsequently rose from 7.8 million recorded passenger journeys in 1996/97, to 15.0 million during 2011/12.