The 2017–18 Ekstraklasa (also known as Lotto Ekstraklasa due to its sponsorship by Totalizator Sportowy, Polish lottery)[4] was the 92nd season of the Polish Football Championship, the 84th season of the highest tier domestic division in the Polish football league system since its establishment in 1927 and the 10th season of the Ekstraklasa under its current title.

The team at the top of the Championship round wins the league title.

The two teams at the bottom of the Relegation round are demoted to I liga for the 2018–19 season.

The defending champions were Legia Warsaw, who won their 12th Polish title the previous season.

Legia successfully defended their title, sealing the league trophy for a 13th time in dramatic circumstances as their deciding game against Lech Poznan was abandoned due to flares and pitch invasions by Lech fans (after Legia went 2-0 ahead).