It is. Finland has two official languages, Finnish and Swedish. One of the biggest minorities in Finland are the Swedish-speaking Finns (suomenruotsalaiset). So it is possible to complete your education either in Finnish or Swedish (and in some schools in Lapland, in Sami languages).
However, I’d like to point out that swedish spoken in finland is quite different from “riksvenska” aka swedish spoken in sweden. Pronunciation is more “finnish”, finnish words are thrown in and mixed with swedish, for example. kind of a similar case as with spanish in spain vs. spanish in south america. Both Swedish and Finnish Swedish are taught in schools.
Anyway. If you are a Finnish-speaking Finn and go to a Finnish-speaking school, you have to study Swedish (”pakkoruotsi” aka “forced swedish” is the common unofficial term for it). But if you are a Swedish-speaking Finn and go to a Swedish-speaking school, you have to study Finnish (tvångfinska).
Finns start to study the other language usually in 7th grade. School is compulsory until 9th grade after which most finns continue either to high school or vocational school. In both schools you have to study Swedish/Finnish at least on some level. The way I have understood most colleges/universities have compulsory Swedish classes.
But yet many.if not most Finns suck at speaking Swedish. There has been a lot of discussion whether Swedish should be made optional or not. We will see.
//EDIT: if you are an immigrant and don’t know Finnish, it is always not compulsory to study Swedish.