Avraham Shlonsky was born to a Hasidic family in Kryukovo (Poltava guberniya, now a part of Kremenchuk, Ukraine). His father, Tuvia, was a Chabad Hasid, and his mother, Tzippora, was a Russian revolutionary. When she was pregnant with her sixth child, she hid illegal posters on her body. Five-year-old Avraham informed on his mother, leading to her arrest. Four of his siblings were prodigies. His younger sister was composer and pianist Verdina Shlonsky. In 1913, when Shlonsky was 13, he was sent to Ottoman Palestine to study at the prestigious Herzliya Hebrew High School in Tel Aviv. When the First World War broke out, he returned to Ukraine.

Shlonsky published his first poem in 1919 in the newspaper Ha-Shiloah. He contributed to Jewish cultural life with songs for satirical stage productions, as well as the Purim holiday costume balls that were a tradition in early Tel Aviv. Even at this early stage in his career as a poet, he showed a tendency for witty writing, incorporating linguistic innovations in the revived and developing Hebrew language. During this period, he edited the literary columns of several newspapers.

In 1921, the whole family moved to Palestine. Tuvia Shlonsky worked as a warehouse manager and bookkeeper in the Shemen factory in Haifa. Avraham was a manual laborer, paving roads and working in construction along with other members of the Third Aliyah. He joined Gdud Ha’avoda and helped to establish Kibbutz Ein Harod in the Jezreel Valley. He married Lucia but conducted a secret affair with Mira Horowitz, the wife of a friend and colleague. She had a child with him in 1936.

In 1933 Shlonsky founded the literary weekly Turim, which was identified with the “Yachdav” society in which major poets Natan Alterman and Leah Goldberg were also members. As an editor, Shlonsky gave aspiring poets an opportunity to publish their poems. Dahlia Ravikovitch merited one such opportunity when her first poem was published in the literary quarterly Orlogin edited by Shlonsky.