Finnish name

In Finland, a person must have a surname and at least one given name with up to four given names permitted. Surnames are inherited either patrilineally or matrilineally, while given names are usually chosen by a person's parents. Finnish names come from a variety of dissimilar traditions that were consolidated only in the early 20th century. The first national act on names came into force in 1921, and it made surnames mandatory. Between 1930 and 1985, the Western Finnish tradition whereby a married woman took her husband's surname was mandatory. Previously in Eastern Finland, this was not necessarily the case. On 1 January 2019, the reformed Act on Forenames and Surnames came into force.
Finnish given names are often of Christian origin, but Finnish and Swedish origins are also common.

Pronunciation

In Finnish, the letter "j" denotes the approximant, as in English you. For example, the two different names Maria and Marja are pronounced nearly identically. The letter "y" denotes the vowel, not found in most dialects of English, but similar to German "ü" and French "u". "R" is rolled. The stress is always on the first syllable in Finnish. For example, Yrjö Kääriäinen is pronounced. Double letters always stand for a geminate or longer sound. As per Finnish phonotactics, both Finnish first names and surnames usually end in vowels, and always in either a vowel or a coronal consonant. This occurs regardless of gender, and surnames are no longer marked by gender.
Pronunciation of Swedish names is similar, but long vowels are not doubled and the stress may be on any syllable. Finland has a long bilingual history and it is not unusual for Finnish speakers to have Swedish surnames or given names. Such names may be pronounced according to Finland–Swedish phonology or, depending on the person named, the person speaking and the language used, a Fennicized variant. For instance, Kronberg may be pronounced as , , or something between the two.
When writing Finnish names without the Finnish alphabet available, the letters "ä" and "ö" are usually replaced with "a" and "o", respectively. This is not the same, but visually recognizable.

Surnames

Finland has three predominant surname traditions: the West Finnish, the East Finnish and that of the Swedish nobility, clergy, bourgeoisie and military. Until the early 20th century, Finland was a predominantly agrarian society and the names of West Finns were based on their association with a particular area, farm, or homestead. Farm names typically had the suffix -la, -lä, i.e. " of", and could refer to the husband or describe the location. This name could change every time the person moved to a different farm. Multiple names could be recorded in documents, such that for example Pentti Jussila l. Penttilä would be a person named Pentti who had moved from Jussila farm to Penttilä farm. Also, even if one had a surname, one would still be better known by the farm name. Farm names, patronyms and village names could be used to disambiguate between different people, but they were not true inherited surnames. For example, in Aleksis Kivi's novel Seven Brothers the character Juhani was officially summoned as Juhani Juhanin-poika Jukola, Toukolan kylästä, in English 'Juhani, son of Juhani, from Jukola farm, Toukola village'.
On the other hand, the East Finnish surname tradition dates back to the 13th century. There, the Savonians pursued slash-and-burn agriculture which necessitated moving several times during a person's lifetime. This in turn required the families to have surnames, which were in wide use among the common folk as early as the 13th century. By the mid-16th century, the East Finnish surnames had become hereditary. Typically, the oldest East Finnish surnames were formed from the first names of the patriarchs of the families. In the 16th, 17th and 18th centuries, new names were most often formed by adding the place name of the former or current place of residence.
In the East Finnish tradition, women carried the family name of their fathers in feminine form indicated by the -tar/''-tär suffix. By the 19th century, this practice fell into disuse due to the influence of Western European surname tradition. Also, women did not change their surnames with marriage.
In 1921, surnames became compulsory for all Finns. At this point, if there was no surname, the homestead names were usually adopted as surnames. Because the inhabitants often included farmhands and other non-family member, holders of the same surname are not necessarily genetically related. A typical feature of such names is the addition of prefixes Ala- or Ali- and Ylä- or Yli-, giving the location of the holding along a waterway in relation to the main holding. In Pohjanmaa, there are similar prefixes Rinta- and Latva-.
Common suffixes are -nen. Initially it was a diminutive suffix usually meaning "small", "junior", and -la/-lä, a locative suffix usually meaning " of". The -nen suffix was freely interchanged with -son or -poika as late as the 16th century, but its meaning was ambiguous as it could refer not only to a "son", but any member of a patriarch's family, a farm or even a place. For example, the surname Tuomonen could mean "Son of Tuomo" or "Farm of Tuomo" or something else belonging to Tuomo. Over time the suffix '-nen' lost its original meaning and became a generic surname-deriving suffix for surnames of so-called Virtanen type, see examples below.
A third tradition of surnames was introduced into Finland by the Swedish-speaking upper and middle classes which used typical German and Swedish surnames. By custom, all Finnish-speaking people who were able to get a position of some status in urban or learned society, discarded their Finnish name, adopting a Swedish, German or a Latin surname. In the case of enlisted soldiers, the new name was given regardless of the wishes of the individual. The oldest noble surnames of Swedish origin were not original, but were derived from the charges in the coat of arms, sigil and flag of the family, for example with Svärd, Kurki/Kurck and Kirves. Families of German origin would use the von prefix.
In the late 19th and early 20th century, the overall modernization process and especially, the political movement of Fennicization brought forth a movement towards the adoption of Finnish surnames. At that time, many people with a Swedish or otherwise foreign surname changed their family name to a Finnish one. The features of nature with endings -o/ö, -nen are typical of the names of this era, as well as more or less direct translations of Swedish names. Fennicizing one's name also concealed non-Finnish origin. For example, Martti Ahtisaari's grandfather was Adolfsen from Norway. Nevertheless, Fennicization was not mandatory and thus it is common to find entirely Finnish-speaking families with Swedish surnames; having a Swedish name does not imply one is a Swedish speaker.
An effect of industrialization was that large numbers of people moved to the cities and towns and had to adopt a surname. Missing an inherited surname, they invented theirs. Initially, these were in Swedish, and they were not very stable; people called them "superfluous names", and a person could change one's surname several times during their career. Later, Finnish became the preferred language, and themes were taken from nature. Some of the most common examples of this type are Laine "wave", Vainio "cultivated field", Nurmi "grassland", and Salo "grove". When applicable, -nen or -la/-lä could be suffixed, such as in Koskinen "rapids + nen".
Sharing a surname does not imply that the two people are related. Regulation of surnames to prevent two families from sharing the same name only began with the 1921 act. Before this, multiple families could have had Fennicized or otherwise changed their surnames to the same name. For example, the Finnish name Rautavaara was adopted by persons with the former Swedish names Sirius, Rosenqvist, Backman, Järnberg, Granlund and Mattson''. Similarly, the adoption of farm names as surnames by unrelated persons living on the same farm contributed to the number of these shared names.

Current use

#	Surname	Etymology	Bearers
1	Korhonen	korho "deaf" or "proud"	23,509
2	Virtanen	virta "stream"	23,374
3	Mäkinen	mäki "hill"	21,263
4	Nieminen	niemi "cape"	21,253
5	Mäkelä	mäki "hill"	19,575
6	Hämäläinen	Häme "Tavastia"	19,242
7	Laine	laine "little wave"	18,881
8	Heikkinen	Heikki < Henrik	17,935
9	Koskinen	koski "rapids"	17,924
10	Järvinen	järvi "lake"	17,040

In 21st century Finland, the use of surnames follows the German model. Every person is legally obliged to have a first and last name. A maximum of four first names are allowed. When marrying, a Finnish couple may adopt a shared surname, either one partner's surname or a combination of their surnames. They may also retain their surnames, either can take one of their spouse's surnames and either can combine their surname with that of their spouse. If they take a shared surname, that will be the surname of their children, otherwise their children can get either parent's surname or a double surname combining those of their parents. Grandparents' names can be used, based on a family's foreign name tradition. When combining double surnames, only one part of each can be used; the double surname can consist of the two individual surnames as such, or combined with a hyphen. Between 1986 and 2018, a spouse could keep their surname, take their spouse's name as a shared surname, or take their spouse's surname as a shared surname but use it in combination with their own as a hyphenated double surname, while their spouse used their original surname. If they had a shared surname, their children got that name, otherwise the surname of either parent would be chosen. Regardless, siblings normally get the same surname.
All persons have the right to change their surname once without any specific reason. A surname that is un-Finnish, contrary to the usages of the Swedish or Finnish languages, or in use by any person resident in Finland cannot be accepted as the new name, unless valid family reasons or religious or national customs give a reason for waiving this requirement. However, persons may change their surname to any surname that has been used by their ancestors, if they can prove such a claim.
Surnames behave like regular words when forming grammatical cases. Thus, for example, the genitive of surname Mäki is Mäen, just like the regular word mäki becomes mäen in the genitive. For given names, this is not always the case even if the name were a common word; for example, Suvi becomes Suvin in the genitive, not Suven.
In 1985, 38% of Finns had a -nen name, 8.9% -la, 7.4% with some other derivative suffix, 17.5% were other Finnish-language names, 14.8% non-Finnish, 13.1% were compound names. Only 0.3% had a double-barreled name.