Profanity in Finnish is used in the form of intensifiers, adjectives, adverbs and particles. There is also an aggressive mood that involves omission of the negative verb ei while implying its meaning with a swear word.

Contemporary Finnish profanity often has old origins; several such words have Pagan roots that after Christian influence were turned from names of deities and spirits to profanity and used as such. In general, the etymology of Finnish swears can be traced either from these formerly religious words or from ancient Finnish words involving excretion or sexual organs or functions. Nowadays, few Finns know of the origins and intended original use of the words, though such definitions have since been compiled in Suuri kirosanakirja ("the great dictionary of profanities"). People of countries neighboring Finland often consider Finnish swear words harsher than their own, and even use heavily mispronounced versions of them, most notably perkele. Native Finns tend to consider the harshness exaggerated, while others use it to their advantage. Finns swear more than their Nordic neighbors or Central Europeans, reaching the same level as Scots or Russians.

Euphemistically, virtually any word can be used in place of profanity by, for example, preceding it with voi (an interjection meaning "oh!"), for example voi paska! (oh shit!) or adding vieköön (third person singular imperative of the verb viedä "to take"), for example hiisi vieköön (may the goblin take it). These were more prominent in older Finnish, e.g. raato is closest to (corpse) or like peto (the beast). There are also other similar non-offensive constructs like taivahan talikynttilät (tallow candles of heaven). There is also an inventory of non-offensive curse words.