Basaksehir beat Kayserispor 1-0 at the Fatih Terim Stadium in the Super Lig on Sunday.
Mahmut Tekdemir scored the only goal of the game on 19 minutes to secure the win.
The Istanbul minnows were crowned champions following the victory.
READ: UEFA move 2020 Champions League final to Lisbon but Istanbul will hold 2021 final
Basaksehir won the league title for the first time in the process, becoming just the sixth different side to do so – joining Bursaspor, Besiktas, Galatasaray, Fenerbahce and Trabzonspor.
Second-placed Trabzonspor bowed out of the title race after being beaten 4-3 by Konyaspor and falling seven points behind the leaders.
Basaksehir came close to winning the league in recent years, finishing runners-up twice over the past three seasons.
Few expected the former municipality side to challenge for the title this season after the architect of the current side Abdullah Avci left Basaksehir for Besiktas.
Okan Buruk was expected to struggle and won just one of his first eight games in charge.
Buruk managed to turn things around and transform his side into the most well organised, balanced and tactically astute team in the league.
The Istanbul side balanced experienced players Gaël Clichy, Robinho, Martin Skrtel and Demba Ba with rising Turkish talents such as Irfan Can Kahveci to build a side that were clearly a cut above the competition.
Buruk has also managed to guide his side to the Europa League Last-16 where they will face Copenhagen – the only Turkish side left in Europe.
Basaksehir won the first-leg of their tie against Copenhagen and could face Manchester United in the next round if they progress.
