Bagir Gasim oglu Seyidzade was born in 1912 in Iravan. Due to the massacres committed by the Armenians in 1918, the Seyidzade family was forced to move to Tbilisi, where B.Seyidzade studied at the Anjuman school. He came to Baku in 1925, worked in a textile factory and studied at the labor faculty, then entered the Azerbaijan Industrial Institute.

In 1932–1939, B.Seyidzade worked in the newspaper “Young worker” and in 1939–1940 he was the responsible secretary and editor of that newspaper. In 1940–1943, he was elected the secretary of the Azerbaijan Youth Union. After completing a one-year diplomacy course in Moscow, he worked as a vice-consul and consul-general in the Soviet consulates in Maku and Tabriz, Iran, in 1944–1949. After returning from Tabriz, in 1949–1952, he was the Minister of Cinematography of the Azerbaijan SSR, and later the Deputy Minister of Culture of the Azerbaijan SSR, the head of the Azerbaijan State Printing and Publishing Department.

Later, B.Seyidzade worked in the Azerbaijan State Radio Broadcasting Committee, and in the last years of his life, he worked as a deputy director of the Telegraph Agency under the Council of Ministers. He was fluent in Russian, French and Persian languages.

B.Seyidzade died in Baku in 1968 and was buried in the Alley of Honor. His daughter, doctor of historical sciences, professor Dilara Seyidzade worked as the head of the Secretariat of the President of the Republic of Azerbaijan.