The 2009–10 Czech First League, known as the Gambrinus liga for sponsorship reasons, was the seventeenth season of the Czech Republic's top-tier football.
Defending champions Slavia Prague could only finish seventh in the league, 21 points behind eventual winners Sparta Prague.
FK Viktoria Žižkov and FC Tescoma Zlín were relegated to the second division after finishing last and second to last, respectively, in the 2008–09 Czech First League.
Bohemians 1905 were promoted from the second division as champions.
Second division runners-up FC Zenit Čáslav decided not to enter the Czech First League and sold the rights to 1.