Safonov was born on 22 September 1895 in Tsaritsyn and completed primary school. He was mobilized into the Imperial Russian Army on 15 May 1915 during World War I and sent to a reserve artillery battalion in Tiflis as a private. In December of that year he was sent to the Caucasus Front, where he served with the 3rd Caucasian Artillery Battalion as a gunner and observer. The battalion was withdrawn to Prokhladny in September 1917, and a month later Safonov left to return to Tsaritsyn as the army disintegrated following the Russian Revolution.