[6] Celtic Football Club was formally constituted at a meeting in St. Mary's church hall in East Rose Street (now Forbes Street), Calton, Glasgow, by Irish Marist Brother Walfrid[7] on 6 November 1887, with the purpose of alleviating poverty in the East End of Glasgow by raising money for the charity Walfrid had instituted, the Poor Children's Dinner Table.

[8] Walfrid's move to establish the club as a means of fund-raising was largely inspired by the example of Hibernian, which was formed out of the immigrant Irish population a few years earlier in Edinburgh.

[9] Walfrid's own suggestion of the name Celtic (pronounced Seltik) was intended to reflect the club's Irish and Scottish roots and was adopted at the same meeting.

[17] Several months later the club moved to its new ground, Celtic Park, and in the following season won the Scottish League Championship for the first time.

[28] He spent over five years in this role, although due to the Second World War no official competitive league football took place during this time.

[43][44] Under the leadership of Stein, the club defeated Inter Milan 2–1 at the Estádio Nacional in Lisbon, on 25 May 1967 to become the first British team,[45][46] and indeed the first from outside Spain, Portugal and Italy to win the European Cup.

He also guided Celtic to their first UEFA Champions League knockout stage in 2006–07[65] and repeated the feat in 2007–08[66] before departing the club in May 2009, after failing to win the SPL title.

[81][82] His first season saw the team go on a long unbeaten run in domestic competitions, during which time the club won their 100th major trophy, defeating Aberdeen 3–0 in the League Cup Final in November 2016.

[85][86] Celtic clinched their fourth treble by defeating Aberdeen 2–1 in the 2017 Scottish Cup Final, the result of which saw the club go through the entire domestic season unbeaten.

[95] In December 2019, Lennon led Celtic to a 1–0 win over Rangers in the 2019 Scottish League Cup Final, the club's tenth consecutive domestic trophy.

The top also featured the Marist Brothers' badge on the right hand side, consisting of a green Celtic cross inside a red circle.

[15] In 1984 Celtic took up shirt sponsorship for the first time, with Fife-based double glazing firm CR Smith having their logo emblazoned on the front of the team jersey.

[15] In March 2015, Celtic agreed a new kit deal worth £30 million with Boston-based sportswear manufacturer New Balance to replace Nike from the start of the 2015–16 season.

[15] In March 2020, Celtic announced a new five-year partnership with Adidas starting on 1 July 2020, in a deal believed to be the biggest kit sponsorship ever in Scottish sport.

[123] Celtic was in a bad financial position in the early 1990s and no major work was carried out until Fergus McCann took control of the club in March 1994.

Rail seating is particularly common in Germany's Bundesliga, most notably at Borussia Dortmund's Westfalenstadion, a ground with a reputation on par with Celtic Park for its intensity and atmosphere.

[141] A study of stadium attendance figures from 2013 to 2018 by the CIES Football Observatory ranked Celtic at 16th in the world during that period, and their proportion of the distribution of spectators in Scotland at 36.5%, the highest of any club in the leagues examined.

Admissions to hospital emergency rooms have been reported to increase ninefold over normal levels[154] and in the period from 1996 to 2003, eight deaths in Glasgow were directly linked to Old Firm matches, and hundreds of assaults.

[159][160] In 2008 and 2010, there were protests by groups of fans over the team wearing the poppy for Remembrance Day, as the symbol is opposed by Irish Republicans owing to its association with the British military.

Celtic was initially founded to raise money for the poor in the East End of Glasgow and the club still retain strong charitable traditions today.

[205] Club chairman Robert Kelly's own family share-holding was of a similar size, and he used his close relationship with the Toomebridge Grants to ensure his power base at Celtic was unchallengeable.

[207] Jimmy McGrory's tenure as manager is generally considered a period of underachievement, but with Chairman Robert Kelly's domineering influence.

[208][209] Even Jock Stein's time as manager ended on a sour note when he was offered a place on the Celtic board, but in a role involving ticket sales.

[213] By the end of the 1980s the Celtic board consisted of chairman McGinn and directors Kevin Kelly, Chris White, Tom Grant and Jimmy Farrell.

[214] In May 1990 the former Lord Provost of Glasgow, Michael Kelly, and property developer Brian Dempsey were invited to join the Celtic board.

However, the directors failed to accompany the wave of economic development facing football in the 1980s, although the club continued to remain successful on the field, albeit limited to the domestic scene in Scotland.

[219] Despite declining attendances and increasing unrest amongst supporters, the Kelly, White and Grant family groupings continued to guard their control of Celtic.

McCann had wanted the ownership of Celtic to be spread as widely as possible and gave first preference to existing shareholders and season-ticket holders, to prevent a new consortium taking over the club.

After he left Celtic, the club were able to invest in players and achieved much success such as winning the treble in 2000–01 and reaching the 2003 UEFA Cup Final.

£10 million of the money raised was for building a new training centre and youth academy, expanding the club's global scouting network and investing in coaching and player development programmes.