He was born in the mansion of his maternal grandfather Muhtar Bey in Rumelihisarı. Abdülhak Şinasi Hisar's childhood was spent in Rumelihisarı, Büyükada and Çamlıca. In 1898, he entered Galatasaray Sultanisi.
Without informing his family, he left Galatasaray Sultanisi in 1905 and went to Paris. He attended the École Libre des Sciences Politiques in Paris until 1908. In Paris, he frequently met with Prince Sebahattin, Dr. Nihat Reşat Belger, Ahmet Rıza Bey and Yahya Kemal.
He returned to Turkey after the declaration of the Second Constitutional Monarchy (1908). He worked for French and German companies, the Ottoman Bank, the Reji Administration, and after 1931 he settled in Ankara and worked for the Ministry of Foreign Affairs. In 1948, he returned to Istanbul and settled in an apartment overlooking the Bosphorus in Ayaspaşa. For a while, he worked as the editor-in-chief of the magazine Türk Yurdu (1954-57). He died of a cerebral hemorrhage at his home in Cihangir in 1963.
He began his literary career in the Armistice years with poetry, book reviews and criticism in Dergâh and Yarın magazines. From 1921 onwards, he became known for his articles in the newspapers İleri and Medeniyet; he also wrote for the magazines 7Ağaç, Varlık, Ülkü and Türk Yurdu, and the newspapers Milliyet, Hâkimiyet-i Milliye and Dünya. Although he was a writer of the Republican period, Hisar remained loyal to the Constitutionalist generation in terms of language and style, and all of his works are mainly based on “memoirs”. In his novels, he adopted the literary approach of writers such as Maurice Barrés, Anatole France and Marcel Proust.
Winner of the 1942 CHP Story and Novel Prize, Fahim Bey and Us was translated into German (Unser Guter Fahim Bey, trans.: Friedrich Von Rummel, 1956). Sermet Sami Uysal (Varlık Publications, 1961) and Necmettin Türinay (M.E.B., 1988) each wrote a book on Abdülhak Şinasi Hisar. After his death, Abdülhak Şinasi Hisar: Seçmeler (Haz.: S. İleri, YK7Y, 1992), Geçmiş Zaman Edipleri (Haz.: T. Yıldırım, Selis, 2005) and Kelime Kavgası: “On Literature and the Novel” (Selis, 2005). Emre Aracı composed a violin concerto of the same name (1997) inspired by the Bosphorus Moonlight.