Gaston Maurice Julia (February 3, 1893 - March 19, 1978) was a French mathematician who devised the formula for the Julia set. His works were popularised by French mathematician Benoit Mandelbrot, and the Julia and Mandelbrot fractals are closely related.

Julia was born in the Algerian town of Sidi Bel Abbes, at the time under French rule. In his youth, he had an interest in mathematics and music. His studies were interrupted at the age of 20, when France got involved in World War I and he was called to serve in the army. In one attack on a cold, stormy night he suffered a severe injury, losing his nose. After many unsuccessful operations to remedy the situation, he resigned himself to wearing a leather strap around the area where his nose was for the rest of his life.

Julia gained attention for his mathematical work after the war when a 199-page article he wrote was featured in the Journal de Mathématiques Pures et Appliquées, a French mathematics journal. The article, which he published in 1918 at the age of 25, titled "Mémoire sur l'itération des fonctions rationnelles" described the iteration of a rational function. The article gained immense popularity among mathematicians and the general population as a whole, and so led to Julia's later receiving of the Grand Prix de l'Académie des Sciences. Despite his fame, his works were all forgotten until the day Benoit Mandelbrot mentioned them in his works, after which he received some national attention.

Julia died in Paris at the age of 85.