The 2019–20 season was Željezničar's 99th in existence and their 20th season in the Premier League BH. Besides competing in the Premier League, the team also competed in the National Cup. In that season, the league ended abruptly on 1 June 2020 due to the COVID-19 pandemic in Bosnia and Herzegovina and by default Željezničar finished in second place, qualifying to the 2020–21 UEFA Europa League qualifying rounds. Season review June On 13 June, Željezničar announced the signing of 24-year-old Filip Erić. On 18 June, Željezničar and Ermin Zec negotiated a three-year contract extension lasting until June 2022. On 20 June, Željezničar announced the signing of 31-year-old Mehmed Alispahić. On 24 June, Željezničar and Siniša Stevanović negotiated a two-year contract extension lasting until May 2021. On 25 June, Željezničar announced the signing of 18-year-old Amar Mehić from Zvijezda Gradačac. On 26 June, Željezničar and Milkos extended their sponsorship agreement. On 27 June, Željezničar signed a sponsorship agreement with Tondach Wienerbeger and Sarajevo Business Consulting. On 27 June, Željezničar announced the signing of 21-year-old Petar Bojo from Mladost Doboj Kakanj. On 28 June, Željezničar and General Logistic extended their partnership agreement. On 29 June, the club announced Admir Džubur as the new Chairman of the club. July On 1 July, Željezničar and Proteam signed a partnership agreement. On 2 July, Željezničar and Porsche BH extended their sponsorship agreement. On 8 July, Željezničar announced the signing of 18-year-old Sedad Subašić from Rudar Kakanj. On 13 July, Željezničar and BBI Banka extended their sponsorship agreement. On 15 July, Željezničar and Perugia completed the transfer of Matej Rodin. On 17 July, Željezničar and Admiral Casino extended their sponsorship agreement. On 17 July, the club announced new home kit for the upcoming season. Following day, the club announced new away kit. On 18 July, the club announced six players will leave on loan to various clubs in the First League of FBiH. On 19 July, Željezničar and Sarajevo osiguranje extended their sponsorship agreement. On 23 July, Željezničar extended their sponsorship agreement with Amko komerc and Farmavita. On 30 July, Željezničar and Rail Cargo Logistics – BH osiguranje extended their sponsorship agreement. August On 2 August, Željezničar announced the signing of 31-year-old Semir Štilić. October On 18 October, Željezničar signed a sponsorship agreement with Imtec. On 22 October, Željezničar signed a sponsorship agreement with Franck. On 24 October, Željezničar signed a sponsorship agreement with Exclusive Change