Baron (from 1789) Johann Möller-Sakomelsky (Russian: Иван Иванович Меллер-Закомельский, Ivan Ivanovich Möller-Zakomelsky); (1725 – 10 October 1790) was a General of the Russian Empire. An artillery expert, he gained fame during the Turkish Wars of the late 18th century.
Born Johann Möller to a family of Lutheran German burghers, he entered the Russian artillery in 1739 as a rank private, and by 1752 had been commissioned as an officer. By 1759 he was a lieutenant-colonel, and saw action in the Seven Years' War. At the Siege of Kolberg in 1761 he gained distinction as commander of the artillery under Rumyantsev, and was later entrusted with organizing and commanding one of the army's first light infantry units. In the following years Möller would continue to be promoted, reaching the rank of lieutenant-general in April 1773.
As a senior officer of Russia's artillery branch, Möller was made a member of the Main Chancellery for Artillery and Fortifications in 1772 and soon became its preeminent member. After the death of Prince Grigory Orlov in 1783 Möller succeeded him as General Feldzeugmeister, the titular head of the Imperial Army's artillery corps (he had been de facto head for several years before that), and was promoted to the rank of general-in-chief.
With the outbreak of war with the Ottoman Empire in 1787, Prince Grigory Potemkin asked Möller to join his field army based out of Ekaterinoslav, and assist in the planning of besieging Ochakov. After the strategic fortress was taken, Möller was awarded with both the Orders of St. Andrew and St. George in the 2nd class alongside the title of baron.