Gabriel Oltramare (19 July 1816, Geneva – 10 April 1906, Les Eaux-Vives, quartier, Geneva) was a Swiss mathematician, known for his book "Essai sur le Calcul de Généralisation".

[4] He was in Egypt from 1843 to 1844 as a tutor for Isma'il, son of Ibrahim Pasha of the Muhammad Ali dynasty.

In 1848 he was appointed professor ordinarius of higher mathematics at the University of Geneva.

In 1893 he published his treatise Essai sur le calcul de généralisation, with 2nd edition in 1899 and a Russian translation in 1895.

He was one of the founders in 1853 of the Institut national genevois and presided from 1894 to 1902 over its section of natural sciences.