Prince Alexei Dmitrievich Obolensky was born on November 24 (December 6) 1855 in St. Petersburg. He came from the ancient princely family of Obolensky and was a significant figure in state administration, holding the positions of chamberlain and procurator of the Holy Synod in 1905 and 1906. He was also the last owner of the estate of Berezichi in the Kaluga province.

Alexei Dmitrievich was the second son of Senator and member of the State Council, Prince Dmitry Alexandrovich Obolensky, and Princess Daria Petrovna Trubetskaya. He was baptized on December 11, 1855, in the Simeon Church, where the godparents were Prince I. L. Shakhovskoy and A. P. Bakhmeteva.

In 1877, he graduated from the Imperial School of Jurisprudence and served in the Life Guards Hussar Regiment. In May of the same year, he was appointed titular counselor in the Ministry of Justice and worked in the 1st Department of the Senate. Soon, he left his service in St. Petersburg and moved to the Kaluga province, where he engaged in elective positions.

In 1881, he was elected honorary justice of the peace for the Kozelsk district and chairman of the congress of justices of the peace. In 1883, he became the Kozelsk district leader of the nobility and was a member of the Kaluga provincial zemstvo assembly. In 1882, he received the title of chamber junker.

In 1894, he was appointed inspector of agriculture in the Ministry of Agriculture and State Properties. He was a member of the first session of the agricultural council. In 1895, he became the manager of the State Noble Land and Peasant Land Banks, and in 1896, he received the rank of actual state councilor and the title of chamberlain.

In May 1897, Obolensky became the deputy minister of internal affairs, participated in the revision of the status of peasants, and headed the land issues commission. In October 1901, due to disagreements with Minister D. S. Sipyagin, he left his position and became a senator.

In 1902 and 1905, he was the deputy minister of finance and headed the management of non-tax revenues and state sales of alcoholic beverages. In April 1905, he was appointed a member of the State Council, where he joined the centrist group.

From the spring of 1905, he again managed the State Noble Land and Peasant Land Banks. From October 1905 to April 1906, in the government of Count S. Y. Witte, he held the position of procurator of the Holy Synod, where the issue of convening the Local Council of the Russian Orthodox Church was being developed. He was one of Witte's closest associates in the development of the October acts of 1905. From April 1906, he was a member of the State Council and an honorary member of the St. Petersburg Committee for Public Sobriety.

According to the memoirs of Prince G. N. Trubetskoy, in 1918, Obolensky lived in Moscow and was known as a Germanophile, willing to sacrifice much for liberation from the Bolsheviks. He later emigrated to Germany and died in Dresden in 1933 after a severe illness.