[7][2] This also makes Rijeka the oldest still active association football club on the territory of today's Republic of Croatia.

While many clubs in town and the region often had specific ethnic leanings, Olimpia intentionally had a very international soul, with Italian, Croatian, Hungarian, and German players all playing and working with each other in unison.

While Olimpia was associated with the wealthier classes, mostly players from working-class families performed for Gloria; therefore, the club found most of its sympathisers among the poorer part of the population.

[12] Olimpia was renamed to Olympia on 9 January 1918 during a meeting of its board and the new president became the Fiuman writer Antonio de Schlemmer, possibly as an anti-irredentist move.

Nonetheless, the players kept playing several matches with other local clubs and against sides organised or brought in by the German occupational authorities.

Worth mentioning are the excessive celebrations for some victories against the German sides that brought several players to be imprisoned and sent to various concentration camps in Germany, and a last ceremonial game between the old legends of Olympia and Gloria that was held on 15 June 1944 while allied planes were bombing the city's surroundings.

Following the liberation of the city from the Nazi occupation and the subsequent occupation by Yugoslav troops, and due to the uncertain future status of the city during the long Paris peace conference, the club resumed its activities in the post-war period under the slightly rebranded name of Rappresentativa Sindacale Fiumana.

The authorities also set up an unofficial city tournament among factories named after Fiumana's late captain Giovanni Maras, who died heroically in partisan combat on the nearby Mount Risnjak.

[13] Despite Maras and most of his colleagues' partisan allegiance and the many hardships endured by them in Nazi concentration camps, the name Fiumana came soon to be considered too Italian for a city that the Yugoslav occupational authorities were trying to annex by force before the official peace treaty could be signed.

The initiative came from Ettore Mazzieri, the city's sports commissioner for the Yugoslav military administration and a previous Fiumana manager.

The first match with the Quarnero identify was played on 7 August 1946, bringing revenge against Hajduk Split for the loss from the previous year.

At the same time, all former Fiumana players and staff carried on playing in the renamed club for the next few years before the Italian exodus slowly forced many of them to leave the city after the season 1947–48.

When the city of Rijeka was assigned to Yugoslavia in February 1947, and Tito broke all ties with Stalin in 1948, most Yugoslav clubs underwent a further re-organisation.

During the early period playing in Yugoslavia's competitions, Kvarner reached moderate success in various national and local leagues.

In 1954, following rising ethnic tensions around the Trieste Crisis and the subsequent elimination of all forms of bilingualism in the city, paired with a desire to have a brand more recognizable and associated the club was further renamed into NK Rijeka.

[22] The club's greatest successes during this period are two Yugoslav Cup titles in 1978 and 1979 and a runner-up finish in 1987, when Rijeka lost the final in the penalty shoot-out.

With one match to play, Rijeka was one point ahead of Croatia Zagreb, needing a home win against Osijek to secure the title.

[27] Following an investigation, 3D analysis revealed Hasančić was not, in fact, in an offside position, and that Rijeka was wrongfully denied their first championship title.

[28][29] An investigation by Nacional revealed Franjo Tuđman, the president of the Republic of Croatia and an ardent Croatia Zagreb supporter, earlier in 1999 ordered the country's intelligence agencies to spy on football referees, officials and journalists, to ensure the Zagreb club wins the league title.

[30] The most memorable result in Europe was the home win (3–1) against eventual winners Real Madrid in the 1984–85 UEFA Cup.

[24] With Rijeka reduced to eight players, Madrid scored two additional goals, progressed to the next round and eventually won the trophy.

In 2013, after winning 4–3 on aggregate against VfB Stuttgart, Rijeka qualified for the 2013–14 UEFA Europa League group stage.

[32][33] Rijeka also participated in the 2014–15 UEFA Europa League group stage, where they defeated Feyenoord and Standard Liège and drew with title-holders and eventual winners Sevilla.

With the privatization process complete by September 2013, Volpi, through Dutch-based Stichting Social Sport Foundation, owned 70% of the club, with the City of Rijeka in control of the remaining 30%.

[38][39] On 29 December 2017 it was announced that chairman Damir Mišković, through London-based Teanna Limited, acquired the majority stake in the club from Stichting Social Sport Foundation.

[40][41] In January 2015, Rijeka sold their star striker Andrej Kramarić to Leicester City for a club-record £9.7 million transfer fee.

During the 1920s, the club was allowed to build a new and, at the time, modern facility in Scoglietto, and toward the end of the decade, it started using Stadion Kantrida as its primary field, naming it Campo Sportivo Olympia.

The group has been active since 1987, but some forms of organised (albeit not registered as associations) support were present and following the club already in the decades before, with the earliest reported in the 1920s.

According to a 2005–07 survey of former players (older than 40 years of age) and respected journalists, Marinko Lazzarich found that the best all-time team of Rijeka is as follows: 1.

[48] In 2020, the club's fans voted to select the best squad over the past decade to fit in a 4–2–3–1 formation: Prskalo – Ristovski, Župarić, Mitrović, Zuta – Kreilach, Moisés – Vešović, Andrijašević, Sharbini – Kramarić.