The club was founded on 19 May 1909, and there were very basic beginnings. Football activity in Most would be interrupted for significant periods of time during World War I and World War II, but even long thereafter, the quality of football in Most remained modest, as Most would play in the lower Czechoslovak leagues from the 1950s all the way through to the 1980s.
In the spring of 2003 the club was bought by Italian industrial gas company SIAD, and the Italian company's involvement sparked a modestly but increasingly successful new era for the club. The club took the name "FK SIAD Most" from the 2003/04 season.
By winning the 2. liga championship in the 2004/05 season, Most finally gained promotion to the Gambrinus Liga, for the 2005/06 season. Extensive reconstruction of the club's stadium - which included the installation of a new pitch, 7,500 seats, and floodlights - was completed in time for the club's first match in the top flight. After a slow start, manager Přemysl Bičovský was dismissed, making way for the arrival of Zdeněk Ščasný. Scasny - a highly regarded manager, who had previously been in charge of Czech clubs AC Sparta Prague and FK Viktoria Žižkov and Greek clubs OFI Crete and Panathinaikos FC - helped the club hold its position in the Gambrinus Liga, guiding the team to a respectable 10th place in the table.
For the 2006/07 season, the club had high expectations, with the ultimate goal being to finish in the top half of the table, but inconsistency would plague the team throughout the season. The team seemed capable of competing with the league's top sides, especially at home - Most managed to draw with AC Sparta Prague (eventual league champions), defeat Slavia Prague (eventual runners-up) and was overall unbeaten at home against the clubs who would finish in the top 5 league positions - but the team was less efficient when playing away from home, and an even bigger problem was an inability to consistently take full advantage of the relatively weaker sides of the league. This translated into Most finishing the season with a league-high 16 draws, good enough only for a somewhat disappointing 12th place in the league, but the club's top-flight status was secured once again.
At the end of the season the club and manager Zdeněk Ščasný mutually decided to end their relationship, and the club hired Robert Žák, who had previously been in charge of the club's youth set-up.