Yevgeny Obolensky was born in family of Prince Pyotr Nikolaevich Obolensky (1760–1833), the future governor of Tula. He was educated at home. At first, he served in the military together with his younger brother Konstantin. In March 1814, they entered the 1st training squadron of the Life Guards Artillery Brigade; on 14 October 1817 they were transferred to the Life Guards Pavlovsky Regiment. Obolensky was a supporter of the unification of the Northern and Southern Societies, and conducted negotiations on this in 1824 with Pavel Pestel.
