On 25 August 2011, Rovers became the first Irish side to reach the group stages of either of the top two European competitions by beating Partizan Belgrade in the play-off round of the Europa League.

[11][12] During the 2024–25 season, Shamrock Rovers became the first Irish side to qualify for the knockout stages of a European tournament as they advanced past the group phase of the UEFA Conference League.

In 1921, Shamrock Rovers were resurrected once more, as a Leinster Senior League outfit, and reached the final of the inaugural FAI Cup, where they lost to St James's Gate in a fixture marred by crowd violence.

During the 1930s, the club won a further three League titles and five FAI Cups with Irish internationals, Paddy Moore and Jimmy Dunne playing key roles in their success, supported by crowds of up to 30,000 people at Glenmalure Park.

[5] In November 1949, following the death of Jimmy Dunne, Paddy Coad accepted the position of player-manager[20] having played with the club for almost eight years, in which time he had established himself as one of the best players in the League of Ireland.

[22] He employed revolutionary training methods with extra emphasis on technical skill and possession which resulted in a fast, passing style of football that contributed significantly to the development of the game in Ireland.

Paddy Ambrose and Ronnie Nolan had remained with the club and were joined by a large selection of signings including Irish internationals, Frank O'Neill and Johnny Fullam.

The club won every domestic honour except the Top Four Competition in the 1963–64 season and were narrowly defeated by holders and eventual finalists, Valencia, in the Inter-Cities Fairs Cup.

[26] Liam Tuohy took over as player-manager and led the club to a further five FAI Cups in succession, completing a series of six,[27] including a 3–0 defeat of League of Ireland champions, Waterford in 1968, in front of 40,000 people at Dalymount Park.

The 1968–69 season saw Mick Leech score a total of 56 goals for the club, including two in the last FAI Cup final of the Six in a Row period, against Cork Celtic.

[37] In 1976, Meagan and Dunne resigned from the club and were replaced by Seán Thomas, the architect of the Six in a Row side, who with limited resources, re-signed Johnny Fullam and Mick Leech,[38] as well as John Conway from Bohemians.

[40] The Kilcoynes implemented a full-time policy and unveiled plans to rebuild Glenmalure Park as a 50,000 all-seater stadium as well as turning the club into a school of excellence for Irish football,[41] capable of challenging for European honours.

In his first season in charge, the club won their 21st FAI Cup, defeating Sligo in a controversial final,[42] but despite that success and emphatic victories in European competition against Apoel Nicosia and Fram Reykjavík,[43] Giles' conservative approach based on possession football proved unsuccessful and on 3 February 1983, he resigned.

[46] On 1 April 1984, the club clinched their first League of Ireland title in 20 years with a 3–1 defeat of Shelbourne and 14 days later against Limerick at Glenmalure Park, midfielder and captain, Pat Byrne was presented with the trophy.

[48] Dermot Keely managed and played for the club that year after McLaughlin's decision to transfer to Derry City [1][49] The Hoops won 74 League games out of 100 from August 1983 to April 1987, losing only 11.

[53][54] Following the completion of the boycott season in Tolka, the Kilcoynes sold the football club to Dublin businessman John McNamara, who put forward a controversial proposal to move in with Bohemians at Dalymount Park.

[56] Ray Treacy managed the League winning side which included Paul Osam, Gino Brazil, John Toal, Alan Byrne and Stephen Geoghegan, who ended the season as top goalscorer.

[59] McGrath unveiled a plan to build a state-of-the-art stadium in the Dublin southwest suburb of Tallaght,[60] and employed Pat Byrne as commercial manager.

[62] In May 1997, Alan McGrath resigned as club chairman and was replaced by Brian Kearney, also of Premier Computers, who succeeded in acquiring planning permission for the new stadium in January 1998.

[63] However, the permission was delayed by objections until November 1998, by which time Joe Colwell had replaced Kearney as chairman and ended Premier Computers' involvement with the club.

In his first season as manager, Liam Buckley guided the club to the FAI Cup final and European qualification, as the team played at Richmond Park.

[66][67] The 2003 season was marked by the club's worsening finances as a deal with potential investor, Conor Clarkson was held up by Mulden's reluctance to sell their land.

[83] The 2009 season proved to be a progressive one for the club, starting with the completion of the stadium and ending with a second-place finish and qualification to the Europa League under the management of Michael O'Neill.

[103] In 2021, despite losing star players such as Jack Byrne and Aaron McEneff, before the start of the season, Shamrock Rovers retained the title, finishing sixteen points ahead of nearest rival St Patrick's Athletic and picking up the trophy before a full house in Tallaght Stadium against Drogheda United.

[117] The next season, the supporters formed an association called Keep Rovers at Milltown and placed a picket on home games at Tolka Park, effectively bankrupting the club's owners.

[118] They accumulated funds, through supporter contributions, in an effort to purchase the stadium but failed to match the offer of a property developer to whom the Kilcoynes eventually sold the site.

[120] However, work on the stadium ceased in 2001 and in March 2005, South Dublin County Council announced that they were taking back the land that they had granted to the club, as the conditions of the planning permission had not been met.

[121] A public consultation process was initiated in July 2005 and a resolution was passed in December 2005 to alter the stadium to accommodate senior GAA games while still having Shamrock Rovers as the preferred tenants.

[174] Their biggest win was a 7–0 aggregate victory (3–0 away, 4–0 home) over Fram Reykjavik in the UEFA Cup first round in September 1982, which remains a record for League of Ireland clubs in European competition.

[175] On 25 August 2011, they became the first Irish team to qualify for the UEFA Europa League group stage when they defeated Partizan Belgrade 2–1 after extra-time in Serbia, for a 3–2 aggregate victory.