Iliya Nikolaev Petrov was born on July 9, 1903 in Razgrad. In 1926, he graduated in painting at the Academy of Arts, Sofia, in the class of Prof. Nikola Marinov. In the same year, he left for specialization in Munich, where he attended the private school of Heinrich Mann and learned from the masters of world painting. From 1928 to 1940, Iliya Petrov worked as a drawing teacher in Sofia. In 1940, he was appointed a teacher at the Academy of Arts. From 1946 he was an associate professor and from 1957 to 1968 - professor of Painting. He was dean of the Faculty of Fine Arts in the period 1957-1962 and rector of the academy from 1965 to 1968. From 1972 he was an academician. Participates in the exhibitions of the "Native Art" Society, is a member of the Society of Independent Artists and the Society of New Artists. In 1944, he was appointed secretary general of the SBH. 

The artistic style in which Iliya Petrov worked in the 20s of the 20th century coincides with the general spirit and atmosphere characteristic of the period. Gradually, his painting became more complex and enriched, leading to the creation of a series of exceptional self-portraits and portraits of famous personalities such as Nikola Marinov, Dora Gabe, Nikolay Rainov, Lyudmil Stoyanov, Emilian Stanev, Vera Tuzsuzova, Svetla Rakitin, Roza Kemalova and others. Iliya Petrov shows real virtuosity and mastery in his landscapes, graphics and animalistic drawings and nudes. His work also includes works with a historical-revolutionary theme, among which the graphic series "Spain" and "September 1923" are particularly expressive.
Iliya Petrov exhibits in all OHI and in many exhibitions abroad. His works are in the possession of the NHG, SGHH, HC in Plovdiv, Pleven, Varna, Burgas, Ruse, Shumen, V. Tarnovo, Kazanlak, the A.S. Pushkin Museum in Moscow, as well as many private collections in the country and abroad.Winner of the Dimitrov Prize (1951, 1959, 1970). Awarded the orders "September 9, 1944", "People's Republic of Bulgaria" - 1st degree (1959), "Kyril and Methodius" - 1st degree, "Georgi Dimitrov" and others. The Narional School of Fine Arts in Sofia is named after him.
He died on May 18, 1975 in Sofia.