He was born Hovhannes (Onik) Karapetyan in the city of Alexandropol, then part of the Russian Empire (now Gyumri, Armenia). His first work called Beginning of Spring was published in 1935. Novelist Atrpet gave the talented poet the epithet "Shiraz", because "this youth's poems have the fragrance of roses, fresh and covered with dew, like the roses of Shiraz." Shiraz being one of Iran's major cities, famous for its roses and poets.

Hovhannes Shiraz studied in Yerevan State University and Moscow Gorky Literary institute. Most of Shiraz's publications were poetry. He is an author of very popular patriotic and love poems included "Ani", "My mother", "May my love remain a secret", "Siamanto and Khjezare", "Expromt", "Like the pagan love", "My holy Homeland", "The fate of Armenians", "To Andranik", etc.

He married famous Armenian poetess Silva Kaputikyan. His son with Kaputikyan, Ara Shiraz, is a sculptor.

A street in Julfa of Isfahan is named after him. In 2005 Levon Mkrtchyan released a documentary film titled "Hovhannes Shiraz: A Documentary".