The White Guard or Civil Guard (Finnish: Suojeluskunta, Swedish: Skyddskr, lit. protection corps) was a voluntary militia, part of the Finnish Whites movement, that emerged victorious over the socialist Red Guards in the Finnish Civil War of 1918. They were generally known as the "White Guard" in the West due to their opposition to the "communist" Red Guards. In the White Army of Finland many participants were recruits, draftees and German-trained Jgers rather than part of the paramilitary. The central organization was named the White Guard Organization, and the organization consisted of local chapters in municipalities.

The Russian revolution of 1905 led to social and political unrest and a breakdown of security in Finland, which was then a Grand Duchy under the rule of the Russian Tsar. Citizen militias formed as a response, but soon these would be transformed along political (left-right) lines. The Russian Revolution of 1917 and the subsequent independence of Finland (declared in December 1917) also caused conflicts in the country. On January 27, 1918, the Finnish government ordered the disarming of all remaining Russian garrisons by the forces of the White Guard, and on the same day the Reds proclaimed revolution, leading to a bloody civil war. White Guards, led by Gen. C. G. E. Mannerheim, constituted the bulk of the victorious White Army during the Finnish Civil War (1918).

After the war the Finnish Defence Forces and a regular police service were founded. From 19191934 White Guards were considered a voluntary part of the army, and separate Guard formations served in the reserve, but in 1934 all defence was consolidated into the regular army and the Guard became a voluntary defence-training organization only. Politically it was neutral, although unofficially it was anti-leftist, clearly anti-Communist, conservative, largely rejected by the labour movement and by the political left. Units of it formed the main forces of the Lapua Movement's abortive coup d'tat (the Mntsl Rebellion) in 1932, however only a small fraction of the Guard participated and the majority of it stayed loyal to the government. White Guardsmen served in the regular army during the Second World War. The White Guard was disbanded according to the terms of the 1947 Finno-Soviet peace treaty after the Second World War.

Similar militias operated in Estonia, Latvia and Lithuania, lands that, like Finland, came under Russian sovereignty until the collapse of Tsarist Russia in 1917. These militias remained in existence until World War II, evolving somewhat into home-guard militias. The phenomenon should be distinguished from the Freikorps established in Germany after its defeat in World War I, although some similarities exist.

The Finnish Civil War was a civil war in Finland in 1918 fought for the leadership and control of the country between White Finland and the Finnish Socialist Workers' Republic (Red Finland) during the country's transition from a grand duchy of the Russian Empire to an independent state. The clashes took place in the context of the national, political, and social turmoil caused by World War I (Eastern Front) in Europe. The war was fought between the "Reds", led by a section of the Social Democratic Party, and the "Whites", conducted by the conservative-based senate and the German Imperial Army. The paramilitary Red Guards, which were composed of industrial and agrarian workers, controlled the cities and industrial centers of southern Finland. The paramilitary White Guards, which consisted of land owners and those in the middle- and upper-classes, controlled rural central and northern Finland, and were led by General C. G. E. Mannerheim.

In the years before the conflict, Finland had experienced rapid population growth, industrialisation, pre-urbanisation and the rise of a comprehensive labour movement. The country's political and governmental systems were in an unstable phase of democratisation and modernisation. The socio-economic condition and education of the population had gradually improved, and national thinking and cultural life had increased. World War I led to the collapse of the Russian Empire, causing a power vacuum in Finland, and the subsequent struggle for dominance led to militarisation and an escalating crisis between the left-leaning labour movement and the conservatives. The Reds carried out an unsuccessful general offensive in February 1918, supplied with weapons by Soviet Russia. A counteroffensive by the Whites began in March, reinforced by the German Empire's military detachments in April. The decisive engagements were the Battles of Tampere and Vyborg, won by the Whites, and the Battles of Helsinki and Lahti, won by German troops, leading to overall victory for the Whites and the German forces. Political violence became a part of this warfare. Around 12,500 Red prisoners died of malnutrition and disease in camps. About 39,000 people, of whom 36,000 were Finns, died in the conflict.

In the immediate aftermath, the Finns passed from Russian governance to the German sphere of influence with a plan to establish a German-led Finnish monarchy. The scheme ended with Germany's defeat in World War I, and Finland instead emerged as an independent, democratic republic. The civil war divided the nation for decades. Finnish society was reunited through social compromises based on a long-term culture of moderate politics and religion and the post-war economic recovery.

The Finnish Civil War of 1918 was the second civil conflict within Finland's borders, as the Cudgel War of 1596-1597 (where poor peasants rose up against the troops, nobles and cavalry who taxed them) has similar features.