Founded as Železnički SK on 28 May 1930,[1] the club became more organized during the 1950s. They changed their name to FK Železnik in 1961, following a merger with FK Napredak, which was originally created by the Ivo Lola Ribar Institute.[1] Between 1963 and 1967, the club competed in the Serbian League North, the third tier of Yugoslav football. They lost to Sloboda Užice in the promotion playoffs to the Yugoslav Second League in 1965.[2]
After the assassination of his father, Dragan "Aca" Bulić took over the club in May 1998.[4] Led by the youngest club president in the history of FR Yugoslavia football, they continued to progress rapidly, finishing in a higher league position every season. Simultaneously, the club reached the semi-finals of the national cup in two consecutive seasons in 2002 and 2003, but was eliminated by Sartid Smederevo on both occasions.[5][6]
In the 2003–04 season, the club achieved its best league performance by finishing in third place, thus securing a spot in the 2004–05 UEFA Cup. They were eliminated by Romanian club Steaua București in the second qualifying round, losing 5–4 on aggregate. Despite only finishing ninth in the league that season, the club made the biggest success in its history by winning the Serbia and Montenegro Cup.[7][8]
Refounded as FK Železnik Lavovi, the club started competing in the Belgrade Third League, the seventh tier of Serbian football. They subsequently earned two promotions in two seasons, reaching the Belgrade First League in 2008. After three years in the fifth tier, the club gained promotion to the Belgrade Zone League in 2011. They subsequently secured promotion to the Serbian League Belgrade in 2012. After spending three seasons in the third tier, the club merged with Radnički Beograd in the summer of 2015.[12]