K
- Kaarlela – became part of the City of Kokkola in 1977
- Kajaanin maalaiskunta – became part of the City of Kajaani in 1977
- Kakskerta – consolidated with Turku in 1968
- Kalanti (formerly known as Uusikirkko Tl.) – became part of the City of Uusikaupunki in 1993
- Kalvola – consolidated with Hämeenlinna in 2009
- Kangaslampi – became part of the City of Varkaus in 2005
- Kanneljärvi – was lost to the USSR in 1944
- Karhula – became part of the City of Kotka in 1977
- Karinainen – was consolidated along with Pöytyä in 2005 to form the municipality of Pöytyä
- Karis – consolidated with Ekenäs and Pohja to form Raseborg in 2009
- Karis landskommun – consolidated with Karis in 1969
- Karjala – became part of Mynämäki in 1977
- Karkku (formerly known as Sastamala) – became part of the City of Vammala in 1973
- Karttula – consolidated with Kuopio in 2011
- Karuna – became part of Sauvo in 1969
- Karunki – became part of the City of Tornio in 1973
- Kaukola – was lost to the USSR in 1944
- Kauvatsa – became part of Kokemäki in 1969
- Keikyä – formed Äetsä along with Kiikka in 1981
- Kemin maalaiskunta – renamed as Keminmaa in 1979
- Kestilä – consolidated with Piippola, Pulkkila and Rantsila to form Siikalatva in 2009
- Kiihtelysvaara – became part of the City of Joensuu in 2005
- Kiikala – consolidated with Salo in 2009
- Kiikka – formed Äetsä along with Keikyä in 1981
- Kimito – consolidated with Dragsfjärd and Västanfjärd to form Kimitoön in 2009
- Kirvu – was lost to the USSR in 1944
- Kisko – consolidated with Salo in 2009
- Kiukainen – consolidated with Eura in 2009
- Kivennapa – was lost to the USSR in 1944
- Kodisjoki – became part of City of Rauma in 2007
- Koijärvi – was divided between Forssa and Urjala in 1969
- Koivisto – was lost to the USSR in 1944
- Koiviston mlk – was lost to the USSR in 1944
- Konginkangas – became part of Äänekoski in 1993
- Korpilahti – consolidated with Jyväskylä in 2009
- Korpiselkä – was partially lost to the USSR in 1944, the rest was incorporated into Tuupovaara in 1946
- Korpo – consolidated with Houtskär, Iniö, Nagu and Pargas to form Väståboland
- Kortesjärvi – consolidated with Kauhava in 2009
- Koskenpää – became part of Jämsänkoski in 1969
- Koski Hl. – renamed as Hämeenkoski in 1995
- Kuhmalahti – consolidated with Kangasala in 2011
- Kuivaniemi – became part of Ii in 2007
- Kullaa – became part of Ulvila in 2005
- Kulosaari – became part of Helsinki in 1946
- Kuolajärvi – renamed as Salla in 1936
- Kuolemajärvi – was lost to the USSR in 1944
- Kuopion maalaiskunta – most of the municipality was incorporated into Kuopio and the rest into Siilinjärvi in 1969
- Kuorevesi – became part of Jämsä in 2001
- Kurkijoki – was lost to the USSR in 1944
- Kuru – consolidated with Ylöjärvi in 2009
- Kuusankoski – consolidated with Kouvola in 2009
- Kuusjoki – consolidated with Salo in 2009
- Kuusjärvi – renamed as Outokummun kauppala in 1968
- Kvevlax became part of Korsholm in 1973
- Kylmäkoski – consolidated with Akaa in 2011
- Kymi – became part of the City of Kotka in 1977
- Kyyrölä – became part of Muolaa in 1934
- Käkisalmen mlk – was lost to the USSR in 1944
- Käkisalmi – was lost to the USSR in 1944
- Kälviä – consolidated with Kokkola in 2009
Read more about this topic: Former Municipalities Of Finland