Fotbal Club FCSB (Romanian pronunciation: [fet͡ʃeseˌbe]), commonly known as FCSB, is a Romanian professional football club based in Bucharest. It has spent its entire history in the Romanian highest tier, the Liga I.

The original FC Steaua București team was part of the namesake CSA Steaua București sports club and belonged to the Ministry of National Defence. In 1998, the club and facilities were separated from the sports club and taken over by a group of shareholders in a post-Ceaușescu privatisation scheme, allegedly leading to one of the shareholders acquiring full ownership five years later. However, CSA Steaua București sued the football club in 2011, claiming that this was a new entity; the two have since been in a legal conflict regarding the ownership of the Steaua brand and honours, which resulted in multiple court cases and the forced change of the name of FC Steaua București to FC FCSB in early 2017.

Domestically, the club has won Liga I 26 times, Cupa Romaniei 24 times, Cupa Ligii 2 times, and Supercupa Romaniei 6 times—all competition records. Internationally, they have won the European Cup and European Super Cup, both in 1986. They reached the European Cup final once again in 1989, when they were defeated by A.C. Milan. Throughout their history, the Roș-albaștrii also played the final of the Intercontinental Cup, the quarter-finals of the European Cup Winners' Cup and the semi-finals of the UEFA Cup.

FCSB's home ground is Arena Naționala, having moved here from the Ministry of National Defence-owned Stadionul Ghencea. Initially, the club played in the colors of the Romanian tricolour—blue, yellow, and red—but yellow soon lost its importance and the team became associated with the red and blue colors. Recently, some kits have begun reintegrating the yellow color.

The club has a long-standing rivalry with neighboring Dinamo București, with matches between the two being commonly referred to as the "Eternal Derby" or the "Romanian Derby".

This page also has a version in other languages:  ФКСБ (@@русский@@)