Gheorghe Ţiţeica (October 4, 1873 in Turnu Severin – February 5, 1939) publishing as George or Georges Tzitzeica) was a Romanian mathematician with important contributions in geometry. He is recognized as the founder of the Romanian school of differential geometry.

He showed an early interest in science, as well as music and literature. Ţiţeica was an accomplished violinist, having studied music since childhood: music was to remain his hobby. While studying at the Carol I High School in Craiova, he contributed to the school's magazine, writing the columns on mathematics and studies of literary critique. After graduation he obtained a scholarship at the preparatory school in Bucharest, where he also was admitted as a student of the mathematics department of the Faculty of Sciences. In June 1895, he graduated with a Bachelor of Mathematics.

In the summer of 1896, after a stint as a substitute teacher at the Bucharest theological seminary, Ţiţeica passed his exams for promotion to a secondary school position, becoming a teacher in Galaţi.

In 1897, on the advice of teachers and friends, Ţiţeica completed his studies at a preparatory school in Paris. Among his mates were Henri Lebesgue and Paul Montel. On June 30, 1899 he defended his master's degree thesis on the framework of oblique curvature, before a board of examiners led by Gaston Darboux.

Upon his return to Romania, Ţiţeica was appointed assistant professor at the University of Bucharest. He was promoted to full professor on May 4, 1900, retaining this position until his death in 1939. He also taught mathematics at the Polytechnic University of Bucharest. In 1913, at age 40, Ţiţeica was elected as a permanent member of the Romanian Academy, replacing Spiru Haret. Later he was appointed in leading roles: in 1922, vice president of the scientific section, in 1928, vice president and in 1929 secretary general. Ţiţeica was also president of the Mathematical Association of Romania, of the Romanian Association of Science and of the Association of the development and the spreading of science. He was a vice president of the Polytechnics Association of Romania and member of the High Council of Public Teaching.

Ţiţeica was elected correspondent of the Association of Sciences of Liège and doctor honoris causa of the University of Warsaw. He was the president of the geometry section at the International Congress of Mathematicians in Toronto (1924), Zürich (1932), and Oslo (1936). In 1926, 1930 and 1937 he gave a series of lectures as titular professor at the Faculty of Sciences in Sorbonne. He also gave many lectures at the University of Brussels (1926) and the University of Rome (1927).

The scientific work of Ţiţeica counts about 400 volumes, of which 96 are scientific projects, most addressing problems of differential geometry. Carrying the researches of the American geometer of German origin Ernest Wilczynski, Ţiţeica discovered a new category of surfaces and a new category of curves which now carry his name. He also studied R-networks in n-dimensional space, defined through Laplace equations.