FKS Stal Mielec (Polish pronunciation: [ˈstal ˈmjɛlɛt͡s]) is a Polish football club based in Mielec, Poland. The club was established on April 10, 1939. Historically, the club has enjoyed great successes within Poland's Ekstraklasa, winning the title twice (in 1973 and 1976) but had undergone significant management changes and financial difficulties within the past two decades, which forced the club from participation in the Poland's top league. After winning the third-tier II liga title in 2016, Stal Mielec was promoted to I liga. After finishing first in I liga in 2020, Stal Mielec was promoted to the Ekstraklasa for the first time since the 1995–96 season.
The football club was one of the first two (next to the volleyball club) at the PZL Mielec, established in 1939. The team was made up of players playing in other clubs in Mielec and employees of the PZL, an aerospace company. In the first match played, the team defeated the Gymnastic Society "Sokół" Mielec with 4–1 victory. Three more matches were played against Dzikovia Tarnobrzeg (2–1), Metal Tarnów (3–1) and a team made up of players from an ammunition factory in Nowa Dęba (6–1). The match against Okęcie Warszawa planned for September did not take place, because World War II started and any sports games were forbidden. However, the matches were played illegally in the meadows beyond the communal forest and in other towns (including Dębica, Kolbuszowa, Sandomierz). The only official match was played against a German military unit and ended with the score 1–2.