From a humble Lesbiote family, he showed an inclination for painting at a very early age. He left the island in 1883 and settled in Smyrna till 1897 when he returned with the aim of enlisting as a volunteer at the front of the Greek-Turkish war. Not being able to return to Turkish-occupied Smyrna, he remained in Thessaly, and specifically Volos, and the villages of Pelion, where he decorated shops, cafes and inns with paintings, but without being accepted by the residents of the area because of his eccentric behavior and appearance. In 1927, Theophilos returned to his birthplace in disappointment where he continued to work till his death. A few years earlier, the art critic Stratis Eleftheriadis, known in the artistic circles of Paris as Teriade, at the recommendation of Fotis Kontoglou and Georgios Gounaropoulos, arranged a meeting with Theophilos and ordered works from him for an exhibition in Paris. The exhibition was at last presented in 1936. In 1965 the Theophilos Museum was opened in Vareia, a gift of Teriade.
In Theophilos’ works — wall paintings, painting on objects or cloth — his world is caught with the ingenuousness and innocence, but also the freshness, of folk painting, a world equally of gods, heroes and everyday human beings, which coexists with elements and images from familiar reality and landscape.