Vasily Stepanovich Zavoyko was born into the family of a military doctor. He received his naval education at the Black Sea navigational school in Nikolaev, after which he was transferred to the Baltic Fleet. From 1834 to 1839 Vasily Zavoyko made two round-the-world voyages. He visited the Pacific Islands, Kamchatka and the northwestern shores of America.

In 1839, Vasily Zavoyko joined the Russian-American Company, heading its trading post in Okhotsk. In 1850, he was appointed military governor of Kamchatka and commander of the Petropavlovsk port. In his new place of service, he embarked on large-scale reforms. Among the buildings constructed during his governorship in the Petropavlovsk port were a wharf, 11 wings, two barracks, private houses, trading shops, a district treasury, and foundries. A brickyard was built in Tarjinskaya Bay, which was later named after Stepan Petrovich Krasheninnikov.

Through the efforts of the governor the life of the city was given a new start and the population quadrupled: while in 1848 there were only 370 inhabitants in the port of Petropavlovsk, in 1854 there were already 1594. The military governor was concerned not only with the life of his subordinates, but also with their health. Vasily Zavoyko headed the smallpox committee and organized mass inoculation of the population. A specialized medical and preventive treatment facility — leprosarium — was built in Paratunka, and temporary hospitals were set up in the villages.

The governor also paid attention to the cultivation of various crops. Cows were imported from Okhotsk to start the Nikolaevskaya cattle farm. A mill was built in Klyuchi, and a weaving workshop for nettle cloth production was established in Milkovo. In 1853, Vasily Zavoyko was promoted to major-general for his distinguished service.

During the Crimean War, Zavoyko organized the defense of Petropavlovsk from the Anglo-French squadron. In November 1854 he was promoted to the rank of Rear Admiral for his services to the Fatherland. In 1855, Vasily Zavoyko was appointed head of the sea and land forces of the Amur region. In 1861, he was promoted to Vice-Admiral, in 1874 — to Admiral. The portrait of the Commander of the Orders of the White Eagle and St. Alexander Nevsky was painted by the Soviet painter Vladimir Ivanovich Zorin in the 1980s.