2018–19 İstanbul Başakşehir F.K. season

The 2018–19 season was İstanbul Başakşehir's fifth consecutive season in the Süper Lig and their 29th year in existence.

Season summary
Başakşehir sat at the top of the Süper Lig table for most of the season and the club looked to be on their way to clinching their first major trophy before losing out to city rivals Galatasaray following defeat to the same club in May 2020. Playmaker Edin Višća was named the Süper Lig player of the season at the end of season awards ceremony.

U21 players
Only professional players and/or players with first team numbers are listed.

Positions by round
The following table represents Başakşehir's positions after each round in the competition.

Fourth round
Başakşehir won 3–1 on aggregate.

Round of 16
Hatayspor won 4–2 on aggregate.

Third qualifying round
Burnley won 1–0 on aggregate.