The wooden structure, which is designed to open and close like a book, marks the site of one of the worst single massacres of Jews during World War II.
More than 34,000 Jewish men, women and children were murdered at the Babyn Yar ravine outside Kyiv on September 29-30, 1941. Over the next three years, tens of thousands more Ukrainian resisters, Roma and disabled individuals were killed at the site. It is estimated that ultimately more than 100,000 people perished there, making it Europe's largest mass grave, according to the Babyn Yar Holocaust Memorial Center.
Friday's ceremony was attended by Ukrainian Prime Minister Denys Shmyhal. It coincided with the country's first "Day of Remembrance for Ukrainians who saved Jews during World War II."
Volodymyr Zelensky, Ukraine's president, released a Twitter statement saying, "Their feat is an example of humanity & self-sacrifice."
The symbolic synagogue, designed by the offices of Manuel Herz Architects in Zurich, Switzerland, is the first building on what is to become a sprawling 370-acre (1.5 square-kilometer) Holocaust memorial site that will include a museum and research center.
The walls of the building, which stands open to the elements when in use, are clad with 100-year-old oak planks salvaged from across the country, linking past to present. "It should be a tree that remembers the world before the Holocaust," said Babyn Yar artistic director Ilya Khrzhanovsky.
The Babyn Yar massacre marked the beginning of the Holocaust in Ukraine, which was then part of the Soviet Union. By 1945, almost all of the country's 1.5 million Jews had been killed. Israel honors 2,659 Ukrainians as Righteous Among the Nations for having saved Jews during that time.