Giovanni Semeria (26 September 1867 – 15 March 1931) was an Italian orator-preacher and author.
He was one of the most high-profile representatives of Italian Catholicism during the early decades of the twentieth century.
In 1912 he founded the Giovine Orchestra Genovese.
Probably his more defining legacy is the Opera nazionale per il Mezzogiorno d'Italia (O.N.P.M.I.
/ loosely, "National Operation for Southern Italy") which he set up with Giovanni Minozzi to create and operate a chain of orphanages and associated educational facilities, addressing an urgent necessity created by the slaughter of the First World War.