It is known that during the 16th and 17th centuries a settlement existed here known as Shuyezersky pogost (a Russian form of the local Karelian name, meaning "swampy lake"). The first documented mention dates from 1589 when Suoyarvi is recorded as church community controlled by the Orthodox community of Sortavala.[citation needed] In 1630, Suoyarvi became an independent community.
An outcome of the Winter War was that most of West Karelia was occupied by the Soviet Union in 1940, when Suoyarvi was granted town status.[citation needed] In August 1941, the territory was re-occupied by Finnish troops, but as part of the wider post-war settlement, it reverted to the Soviets in 1944; it was the second largest territory by area (after Petsamo) ceded by Finland to the Soviet Union following the Continuation War. Before the occupation, Suoyarvi was geographically the easternmost municipality of Finland.
Suoyarvi had its own dialects of the Karelian language before the area was ceded to the Soviet Union and its inhabitants were relocated to other parts of Finland. Most of the Karelian people in the former municipality spoke a variety of South Karelian (suvikarjala), while the villages in the Hyrsylä (Khyursyulya) salient, which also included Ignoila (Ignoyla) and Hautavaara (Khautavaara), spoke a Livvi dialect instead.
Законодательное Собрание Республики Карелия.Закон№871-ЗРКот29 апреля 2005 г. «Об административно-территориальном устройстве Республики Карелия», в ред. Закона №1895-ЗРK от2 июня 2015 г.«О внесении изменения статью9 Закона Республики Карелия "Об административно-территориальном устройстве Республики Карелия"». Вступил в силусо дня официального опубликования. Опубликован: газета "Карелия", №48, 7 мая 2005 г. (Legislative Assembly of the Republic of Karelia.Law#871-ZRKofApril29, 2005 On the Administrative-Territorial Structure of the Republic of Karelia, as amended by the Law#1895-ZRK ofJune2, 2015 On Amending Article9 of the Law of the Republic of Karelia "On the Administrative-Territorial Structure of the Republic of Karelia". Effective as ofthe official publication date.).
Законодательное Собрание Республики Карелия.Закон№813-ЗРКот1 ноября 2004 г. «О городских, сельских поселениях в Республике Карелия», в ред. Закона №1694-ЗРK от2 апреля 2013 г.«О преобразовании муниципальных образований "Нюхчинское сельское поселение" и "Сумпосадское сельское поселение" Беломорского муниципального района и внесении изменений в некоторые законодательные акты Республики Карелия». Вступил в силупо истечении десяти дней со дня официального опубликования. Опубликован: газета "Карелия", №124, 126, 129, 132, 135, 136, 139, 4 ноября— 9 декабря 2004 г. (Legislative Assembly of the Republic of Karelia.Law#813-ZRKofNovember1, 2004 On the Urban, Rural Settlements in the Republic of Karelia, as amended by the Law#1694-ZRK ofApril2, 2013 On the Transformation of the Municipal Formations of "Nyukhchinskoye Rural Settlement" and "Sumposadskoye Rural Settlement" of Belomorsky Municipal District of the Republic of Karelia and on Amending Various Legislative Acts of the Republic of Karelia. Effective as ofthe day which is ten days after the day of the official publication.).
Законодательное Собрание Республики Карелия.Закон№825-ЗРКот1 декабря 2004 г. «О муниципальных районах в Республике Карелия», в ред. Закона №1694-ЗРK от2 апреля 2013 г.«О преобразовании муниципальных образований "Нюхчинское сельское поселение" и "Сумпосадское сельское поселение" Беломорского муниципального района и внесении изменений в некоторые законодательные акты Республики Карелия». Вступил в силупо истечении десяти дней со дня официального опубликования. Опубликован: газета "Карелия", №141, 16 декабря 2004 г. (Legislative Assembly of the Republic of Karelia.Law#825-ZRKofDecember1, 2004 On the Municipal Districts in the Republic of Karelia, as amended by the Law#1694-ZRK ofApril2, 2013 On the Transformation of the Municipal Formations of "Nyukhchinskoye Rural Settlement" and "Sumposadskoye Rural Settlement" of Belomorsky Municipal District of the Republic of Karelia and on Amending Various Legislative Acts of the Republic of Karelia. Effective as ofthe day which is ten days after the day of the official publication.).