Ykk?nen (Finnish for 'Number One') is the first division of the Finnish football league system as managed by the Football Association of Finland. It is, however, overall only the second highest level in Finnish football, as the Veikkausliiga is managed independently of the Football Association and serves as the highest division.

Like the Veikkausliiga, the first division is played mainly during the summer. The division has 14 clubs, all of whom play two matches against all other clubs in the division. The winner of the Ykk?nen attains promotion directly to the Veikkausliiga, while the second placed team plays a two-legged knockout tie with the second-last team of the Veikkausliiga, and the winner of this tie remains in or is promoted to the top division.

A similar promotion/relegation system takes place between the Ykk?nen and the Kakkonen ('second division', or the third level of Finnish football), with the bottom two teams being relegated and the next two playing knockout ties with two teams from Kakkonen.