Mikhail Vasiliyevich Alekseeev (Russian: Алексеев, Михаил Васильевич) (November 3, 1857 — September 25, 1918) was a Russian military officer before and during World War I, and one of the leaders of counterrevolutionary forces in 1917-1918.

Born in Kalinin, his father Vasilii Alekseev was an army captain in the 64th Kazan Regiment. Mikhail Alekseev graduated from the Moscow Infantry School in 1876 and was made an ensign in the 64th Kazan Regiment. He completed studies at the Nicholas General Staff Academy in 1890 and was posted as a senior adjutant in the headquarters of the 1st Army Corps in the St.-Petersburg Military District. He served in this capacity and as a professor at the Academy's Department of Military History from 1898-1904. With the outbreak of the Russo-Japanese War, in October 1904 Alekseev was appointed Quartermaster General of the 3rd Manchurian Army. During the war he was awarded a gold sword and the orders of St. Stanislav 1st class with sword and St. Anne 1st class. After the war M.V. Alekseev was named first senior quartermaster of the General Staff’s main directorate, while maintaining his position as professor at the General Staff Academy. In 1908 he was made Chief of Staff of the Kiev military district. In 1912 Alekseev was named commander of the 13th Army corps. At the beginning of World War I in August 1914, he was appointed Chief of Staff of the Southwestern front (which held the Third, Fourth, Fifth, and Eighth Armies) where he planned the Russian offensive into Galicia, and given the rank of general-of-infantry. In March 1915 Alekseev became a commander of the Russian Western front. When Grand Duke Nicholas Nikolayevich of Russia stepped down as Russian supreme Commander-in-chief in August 1915 and replaced by Tsar Nicholas II, Alekseev was appointed to Chief of Staff of the General Headquarters (Stavka) and placed in charge of all military operations. He served in this capacity from August 1915 to March 1917.

During the February Revolution of 1917, Alekseev tried to save the monarchy and was chosen to convince the Tsar to abdicate the throne in March 1917. From March to May 1917 Alekseev was the Commander-in-chief and later adviser to the Provisional Government. He spoke against the Soviets and democratization of the army, and was one of the initiators of the counterrevolutionary organizations.

On August 30, 1917 Alekseev became Chief of Staff of the Stavka under Commander-in-Chief Alexander Kerensky. His goal was to prevent the Kornilov movement (see Kornilov Affair) from developing into civil war. That same day, Alekseev arrived at the General Headquarters, arrested General Kornilov and his men and sent them to prison in Bykhov (a town in Mogilev oblast in Belarus), from which they would "break away" with the help of General Nikolai Dukhonin . He then resigned his post in protest of Kerensky's policies.

After the November Revolution, Alekseev fled to Novocherkassk, where on November 15 he began forming the so called Alekseev's Officer Organization, which would become the basis of the Volunteer Army. In December 1917, Kornilov became the leader of Alekseev's organization, with Alekseev himself dealing with its political and financial affairs.

Alekseev was appointed head of the so called Special Council, which would function as a government under Anton Denikin, after the death of Kornilov in April 1918.

Alekseev died of a heart condition in Ekaterinodar. He was first buried in the crypt of the cossack host cathedral, but later his body was taken by his family to Belgrade, where it remains.