The Football Association's licensing committee's decision was unanimous, and came as a result of the club's weak financial position.
The FA says the timetable is too tight to promote a club to take Oulu's place to give a full complement of 14 clubs.
FA CEO Kimmo J Lipponen said that although Veikkausliiga clubs would have preferred to play with 14 clubs, they understood that this was not possible at such a late stage.
The FA had already announced a plan to reduce the number of teams in the top flight over time.