Željezničar always had great support from fans all over Bosnia and Herzegovina and Yugoslavia. When Željeznicar won Yugoslav First League in 1971–72 season, fans followed their club across Yugoslavia. In 1976–77 season Željeznicar was relegated from Yugoslav First League, but that didn't stop fans to follow Željo in second league, so the average attendance at Grbavica Stadium was 10 000 which wasn't often in Yugoslav Second League, and after one season in second league Željeznicar won promotion and was again in first league. During that time the most passionate Željeznicar fans were located on the south stand of Grbavica Stadium. Željeznicar was a club supported mainly by working class citizens, and their city rivals FK Sarajevo by upper class. In 1981 Zeljeznicar played in Yugoslav Cup finals against FK Velez Mostar. Match was played at Marakana stadium, and attendance was 40 000. The Željeznicar fans were on the east side of stadium. Despite the great support Željo lost the finals. The best moments oh their history Željeznicar had when they played the semi-finals of UEFA Cup in 1984–85 season. That year except in SarajevoŽeljo had a support in other cities such as Konjic, Travnik, Lukavac and there was a group of Željo fans in Novi Sad. In 1987 the most passionate fans of Željeznicar formed an ultras group called The Maniacs. The Maniacs are located on south stand of Grbavica. There was also formed subgroups Blue Tigers and Joint Union. For the next years Maniacs become one of the famous supporter groups in country. They followed Zeljo in Belgrade, Zagreb, Ljubljana and other cities across Yugoslavia. After the breakup of Yugoslavia and when Bosnian War start, Grbavica a quarter of the city of Sarajevo where Grbavica Stadium is located was on front lines of battle between Bosnian army and Bosnian Serbs forces. Many members of The Maniacs joined Army of the Republic of Bosnia and Herzegovina and Zelene beretke. One of them was Dževad Begić-Đilda. He was one of the founders and leader of The Maniacs. Dževad Begić was killed 1992 by sniper shot when he was trying to save wounded civilians. The most important day of every Maniac is 2 May 1996 when Željezničar played their first match on Grbavica Stadium after war, the stadium was rebuilt because of heavy structural damage. That day in front of 20 000SarajevansFK Željezničar Sarajevo played against FK Sarajevo. The game end in a draw 1:1.
Surprisingly there is a group of Maniacs in Argentinian city called Mar del Plata. Their leader Marcelo Torre is passionate fan of Boca Juniors, he met a girl from Sarajevo who is a Željo fan and after he visit her and meet Željo fans his love to club started. Torre has several times visited Grbavica Stadium and when he went home for first time he bring with him seven FK Željezničar jerseys for his friends. Currently Maniacs Mar del Plata have eight members. The group is divided in fans of Boca Juniors and River Plate but the love for FK Željezničar is the one that connects them.
Notable supporters
Željezničar had many famous supporters, some of them are:
Mladen Vojičić Tifa – rock musician. His song Grbavica became an anthem of The Maniacs and they singing that song in every home match
