QSL Chairman and Qatar Football Association President Sheikh Hamad bin Khalifa bin Ahmed Al Thani announced the plans for expansion on Monday.
The decision to increase the number of teams means Al Sailiya – who finished bottom of the League – will avoid relegation. Second Division champions Al Ahli and runners-up Muaither will join the top flight.
The Second Division and the Reserve League will merge to create an 18-team second tier.
Doha Stadium Plus had exclusively reported the expansion plans a couple of months ago.