He was born in Turnu Severin, western Oltenia, the son of Anca (née Ciolănescu) and Radu Țiței, originally from Cilibia, in Buzău County.

His teachers there included David Emmanuel, Spiru Haret, Constantin Gogu, Dimitrie Petrescu, and Iacob Lahovary.

After ranking first in his class and earning a second undergraduate degree from the Sorbonne in 1897, he was admitted at the École Normale Supérieure, where he took classes with Paul Appell, Gaston Darboux, Édouard Goursat, Charles Hermite, Gabriel Koenigs, Émile Picard, Henri Poincaré, and Jules Tannery.

[4] Țițeica chose Darboux to be his thesis advisor; after working for two years on his doctoral dissertation, titled Sur les congruences cycliques et sur les systèmes triplement conjugués, he defended it on 30 June 1899 before a board of examiners consisting of Darboux (as chair), Goursat, and Koenigs.

[2] Țițeica was the president of the geometry section at the International Congress of Mathematicians (ICM) in Toronto (1924), Zürich (1932), and Oslo (1936).

Țițeica married Florence Thierin (1882–1965) and the couple had three children — Radu (1905–1987), Gabriela (1907–1987), and Șerban (1908–1985) — all of whom pursued careers in academia;[10][11] the youngest one became a renowned quantum physicist.

The family lived in a 19th-century house on Dionisie Lupu Street, close to Lahovari Plaza, in Sector 1 of Bucharest; Țițeica moved there around 1913, when he was elected to the academy.

[15] The logo of the 40th International Mathematical Olympiad, held in Bucharest in 1999,[16] was inspired by Țițeica's 5 lei coin problem.