The name Gena is a diminutive form of the Russian name Gennady, which is derived from the Greek name Gennadios. The name Gennadios is a combination of the Greek words "gennados" meaning "noble" and "gennaios" meaning "generous" or "magnanimous." It is believed to have originated in the Byzantine Empire during the medieval period.

During the Christian era, the name Gennadios gained popularity as it was borne by several early saints and church figures. One of the most notable was Saint Gennadius of Constantinople, who served as the Patriarch of Constantinople in the 5th century AD. Another significant figure was Gennadius of Marseilles, a 5th-century priest and theologian who authored a treatise on the lives of various Christian writers.

The earliest recorded use of the name Gena as a diminutive form can be traced back to the 19th century in Russia. It became particularly popular after the Russian Revolution of 1917, as many traditional names were shortened or modified to fit the new cultural norms. Notable historical figures with the name Gena include the Soviet actress Gena Rowlands (born 1930), who was of Ukrainian descent, and the Russian actress Gena Dimitrova (1941-2005).

Another prominent bearer of the name was Gena Turgel (1924-2018), a Polish-born Israeli sculptor and painter who survived the Holocaust and went on to create numerous public artworks and memorials. The name Gena was also borne by the American author and journalist Gena Rowlands (1909-1973), who wrote several novels and biographies.

In the field of science, Gena Samoilova (1892-1962) was a Soviet botanist and plant physiologist who made significant contributions to the understanding of plant respiration and photosynthesis. She was elected as a corresponding member of the Soviet Academy of Sciences in 1958.

While the name Gena may have originated from the Greek and Russian cultural spheres, it has since gained popularity in various parts of the world, particularly in Eastern Europe and the United States. However, its roots can be traced back to the rich historical and linguistic traditions of the Byzantine Empire and the early Christian era.