Georgios Roilos studied at the School of Fine Arts, Athens from 1880 until 1887. He studied painting under Nikiforos Lytras and etching under Aristidis Rovertos.

Later in 1888 on a scholarship from the Kritsis Bequest, he studied at the studio of Nikolaos Gysis at the Royal Academy of Fine Arts in Munich.

A year later he moved to Paris and continued his studies at the Académie Julian under J. P. Laurens and B. Constant. In 1894 he returned to Greece.

From 1895 until 1903 he held a teaching position at the School of Fine Arts, Athens.

In 1904 he moved to London where he stayed for four years. Two years after returning to Athens permanently, he took up another teaching position at the School of Fine Arts, Athens from where he retired in 1927.

His work, like that of his peers, is defined by academism with influences from nineteenth-century French realistic and impressionist movements. He was an admirer of the work of Eugene Delacroix, Gustave Courbet and John Constable and is one of the first Greek painters who depicted Greek nature and its atmospheric variations with a poetic feeling.

Roilos fought in the Greco-Turkish war of 1897 and the first Balkan Wars between 1912 and 1913. For these two wars, he produced a large number of works of unparalleled quality that documented battles and other war scenes.

He held many solo exhibitions in Athens and participated in several prestigious group exhibitions such as the 1889 Exposition Universelle in Paris and an exhibition at the Royal Academy, London in 1905.

His work is found in many public and private collections, notably: The National Gallery, Athens, the Athens Municipal Gallery, the Leventis Gallery, the Koutlides Collection and the National Bank of Greece collection.