In 1890 he emigrated with his family to Argentina, to Buenos Aires, where an unidentified painter gave him drawing lessons and encouraged him to continue his education.
So, when the family, returned home, settled in Fiesole, Giovanni studied fine arts in Florence, having as a teacher, among others, Giovanni Fattori, with whom he remained in relationships even over the years later.
After a year of study in Venice, he received a grant from the Municipality of Forlì to attend the Academy of Fine Arts in Rome.
In 1901 he made The narrator horse the masterpiece of the symbolist phase of Marchini, a great oil on canvas that will be exhibited in Milan in 1903, arousing considerable clamour.
In 1904, with Antonio Ghisu and Cesare Averardi, he went to Naples on foot. he stayed there for a few months and was very impressed with the works of the Posillipo school.
Its typical themes are nature, in the sense of landscapes and in the sense of the relationship between animals and man, and society, in peculiar, the world of the humble.
Realism and references to symbolism are always present in his work.
After having frescoed the Palazzo Paganelli Rivalta at Terra del Sole (1910-1911) and the dedicated chapel at St. Anthony of Padua in the Church of St. Francis in Forlì (1913),
he left voluntarily for the First World War. Of this experience, we still have small-sized works. After the war, he returned to painting at the easel but also to the fresco activity,
In 1920, with don Tommaso Nediani, he founded the Cenacolo Artistico Forlivese. In 1923 he married the painter Vittoria Benatti from whom he had two children.
His works were exhibited at the Permanent Exhibition of Milan in 1922 and at the Exposition Biennial of Rome in 1925. Other frescoes were commissioned for the villa Dettoni in San Pietro
in Cariano (1928), near Verona, and for the Cathedral of St. Peter the Apostle of Senigallia (1931). In 1929, fascinated by the Apennine landscapes, he bought the house called "il Raggio",
located in the homonymous locality two kilometres from the Mandrioli pass. Among his works almost entirely lost, one can remember the allegorical figures for the new Palazzo delle Poste di Forlì, dating back to 1932,
In addition to paintings, he also performed works with other techniques, from woodcut to plastic arts.
Giovanni Marchini died in Forlì on 18 February 1946.