Glentoran was founded in 1882 by the workers of the Protestant-dominated Harland & Wolff shipyard, and draws much of its identity from its industrial roots in East Belfast.

[1] In 1889, Glentoran FC was established as a limited company, and benefited from investments by local industrial leaders Viscount Pirrie and G.W.

[3] The Irish League was established in 1890, with Glentoran being among the founding members, alongside Clarence, Cliftonville, Distillery, Linfield, Milford, Oldpark and Ulster.

The final match was decisive, and Glentoran secured a convincing victory to win the Vienna Cup, making them the first British team to claim a European trophy.

In November 1973, Glentoran made history by becoming the first Irish club to reach the quarter-finals of the competition with a 3–1 victory over Brann in Belfast, following a 1–1 draw in Bergen.

In Coyle's first cup final in charge he gave up the right to lead the team out, instead he asked long serving Kitman Teddy Horner have this honour.

In the 93rd minute of the match, Glentoran, who needed victory in order to have a chance of clinching the league title, scored a goal via their centre forward (and former Linfield player) Chris Morgan.

[18] Less than a week later, Glentoran appointed Alan McDonald as manager, replacing Roy Walker, who stepped down but vowed not to rest until director of football Tom Dick resigned.

Since then, notable signings at the club include Matthew Burrows, from Dundela (where he scored fifty-three goals last term), Johnny Taylor (from Hearts) and former Lisburn Distillery player Andy Waterworth for a fee of £30,000.

However, Glentoran's start to the season was delayed by a referee strike led by their association's Chairman, David Malcolm, citing higher wage demands.

Glentoran's only summer signings for 2009 were Richard Clarke from Newry City and Northern Ireland international Keith Gillespie on a free transfer.

[citation needed] In March 2010, after McDonald resigned, former player Scott Young was put in charge of the Glens until the end of the 2010–11 season along with Pete Batey as assistant manager and Tim McCann as head coach.

Gary Hamilton went out on loan to Glenavon, and back in December 2011 took on the role as manager of the club (after the resignation of Marty Quinn), after being released of his playing obligations by Glentoran.

A fundraising organisation, Spirit of '41 (which was named after the year when The Oval was bombed by Germans and the massive effort to rebuild it) was set up, and to this day has raised over £25,000.

On 12 January 2011, a special EGM was held which set out the proposals that would save Glentoran from oblivion and change radically how the club is run.

On 7 July 2011, Glentoran beat Macedonian side FK Renova in the Europa League first qualifying round after the Glens overturned a 2–1 away defeat by winning the home leg 2–1 at The Oval and thus levelling the score on aggregate.

Despite beating Linfield three times, Glentoran lost in the County Antrim Shield final to Cliftonville and continued their losing streak in the league.

The Glens then secured a 0–0 home draw against Coleraine in a top of the table clash before defeating Lisburn Distillery 3–0 a week later.

Three wins, a draw, and two defeats which included a disappointing 2–1 loss away to Donegal Celtic, left the Glens sitting in fifth place in the league at the end of November, twelve points behind pacesetters Cliftonville.

However, the season ended on a high note as the Glens overcame favourites and newly crowned league champions Cliftonville 3–1 after extra time in the Irish Cup final on 4 May 2013.

The game was played at The Oval because construction work at Windsor park had gone wrong and the Kop stand was deemed unstable and needed to be knocked down.

[20] Kernaghan started with some promising results and managed to end the 2015/16 season in 5th Position.The Glens made several signings that summer in the hope of returning to the top 3 and returning to regular European football signing included former Ballymena United goalkeeper Dwayne Nelson, Portadown defender Ross Redman, resigned former player James Ferrin, Eric Foley from Galway United and the signing of Rangers Spanish legend Nacho Novo the Glens started the season inconsistently with two 1–0 wins against Dungannon Swifts and Portadown and two defeats against Cliftonville and struggling Carrick Rangers.

In January 2017, Glentoran suffered a 2–1 Irish Cup 5th Round defeat at the Oval to fierce rivals Linfield after extra time.

[22] Mick McDermott became Glentoran manager as part of a deal involving new investment in the club, which was approved by 96% of shareholders at an EGM on 16 May 2019.

[25][26] On 4 February 2020, the Glentoran Chairman Stephen Henderson announced on behalf of the club, that it was finally free of external debt.

[27] During McDermott's first full season in charge at the East Belfast club, he and Millar led the side to victory in the Irish Cup final on 31 July 2020.

This move was one in that was viewed controversially by many Glentoran supporters, with Feeney’s Linfield history and lack of managerial success being two of the biggest sticking points with Glens fans.

The club's board of directors have suggested moving close to Comber, well outside the city bounds of Belfast, which the majority of supporters firmly oppose.

On 24 May 2016, supporters approved a board recommendation, at the club end of season AGM, to demolish and redevelop The Oval into a modern new community-based stadium, over alternative proposed moves to sites at Sydenham and Titanic Quarter.

Funding will come from a £10million amount that has been on hold for the Glens under the Government's £110m sports grounds improvement programme that has led to the creation of the new Windsor Park and Ulster Rugby's Kingspan Stadium in tandem with redevelopment at venues across the country.