Fatih Terim's side have now won their domestic league 19 times, making them the most successful team in the competition's history
Striker Burak Yilmaz scored twice, while midfielder Selcuk Inan was also on target with a double on a vociferous occasion at the Turk Telekom Arena.
The last 10 minutes did not go to plan, with the visitors netting two consolation strikes and Umut Bulut receiving a red card, but by then the title celebrations were already well under way.
Fatih Terim’s team have now won the league 19 times in their history, with this success moving them above Fenerbahce's 18 at the outright top of the all-time list. Besiktas come third with 13 titles.
With three games left to play going into the weekend, Gala had held a seven-point advantage over rivals Fener, who had lost to Benfica in the Europa League semi-finals earlier this week.
That meant Gala’s victory sealed the title, although ultimately even a defeat would have been enough as Aykut Kocaman’s side suffered a disappointing 2-0 defeat to relegation candidates Istanbul BB.
January signings Didier Drogba and Wesley Sneijder both started the match, with the Dutchman replaced on 58 minutes, while the Ivorian played the full game alongside Burak in attack.
Gala have won seven domestic games in a row and face rivals Fenerbahce next week with the title already in the bag before rounding off the league season against Trabzonspor.