The building opened in 1867 as the Royal Colosseum and Opera House under the management of James Baylis, who already ran the Milton Colosseum Music Hall at Cowcaddens Cross and had opened the Scotia Music Hall down on Stockwell Street. He was a Glasgow showman with multiple irons in multiple fires. Two years later he leased the new venue to Glover and Francis, who had previously run the old Theatre Royal in Dunlop Street before it was demolished to make way for St Enoch railway station. William Glover brought the name Theatre Royal with him - along with his company of actors, orchestra, and stage crew - and the building was rebranded. From its earliest years it specialized in opera, presenting many Scottish premieres of works both famous and now-forgotten.

The 1879 fire gave Charles J. Phipps, then the most sought-after theatre architect in Britain, the chance to rebuild the auditorium from scratch. He turned the front door away from Cowcaddens Road to face Hope Street, expanded the building into a classical French Renaissance design with three galleries instead of two, and gave it capacity for around 3,000 people in an era when audiences sat closer together than they do now. It is this auditorium - in its essentials - that still stands. When fire returned in 1895, Phipps oversaw the rebuild again, restoring his design within six months and few visible changes. The same year, the resident company became Howard and Wyndham Ltd, quoted on stock exchanges, and grew into the largest group of quality theatres in Scotland and England, with the Royal as flagship.

In 1888, Baillie Michael Simons arranged for two actor-managers, James Howard and Fred Wyndham, to take the theatre on. They announced an ambitious programme: plays, opera, musicals, summer revues, and above all pantomime. Their first was The Forty Thieves. Howard and Wyndham went on to produce pantomimes across Britain for nearly 80 years. From the 1930s they staged the famous Half Past Eight Shows, later rebranded as the record-breaking Five Past Eight Shows. They never operated music halls - that was Moss Empires' territory - but they built the King's Theatre across the city in 1904, designed by Frank Matcham, and kept the Theatre Royal as the centerpiece of their empire. Simons himself was a Glasgow cultural entrepreneur whose touch also lay behind Kelvingrove Art Gallery, the International Exhibitions of 1888 and 1901, and the expansion of the McLellan Galleries.

In 1957 Scottish Television leased the theatre, transmitting variety, dance and music programmes from its stage and networking them to ITV areas south of the border. STV became one of the earliest and largest sponsors of Scottish Opera, founded by Sir Alexander Gibson in 1962. The 1969 fire, in which a fireman lost his life, paused operations. STV moved most of its productions temporarily to its Edinburgh branch. In 1974, STV moved next door to custom-built premises and offered the theatre to Scottish Opera, which bought it with public support. The company turned it into Scotland's first national opera house, enlarging the orchestra pit to hold a hundred players, modernizing the dressing rooms, restoring the plasterwork to its original cream, gold, and pale blue, and hanging William Morris wallpaper on the principal walls. The reopening on 14 October 1975 was a televised gala performance of Die Fledermaus, with the Duke of Edinburgh on hand to open the building.

In 1997, lottery funding paid for new wiring and a fresh colour scheme - cherry-red walls, turquoise seats - replacing the 1975 palette. In 2005 Scottish Opera leased the management to Ambassador Theatre Group while keeping the building as its home, and Scottish Ballet's. The most dramatic recent change came in December 2014, when a 14-million-pound, largely elliptical new foyer building opened at the corner of Hope Street and Cowcaddens. Designed by Page and Park on the site of the former Alexandra Music Hall, it added entrances, bars, a cafe, hospitality and education space, a heritage exhibition, and lifts to every level including an open roof terrace - all wrapped around an open spiral staircase. Since 1977 the older theatre has been protected as a Category A listed building. It has burned three times. It has been rebuilt three times. It is still selling tickets.