John Laskaris Kalopheros (1325/30–1392) was a wealthy Byzantine aristocrat who converted to Catholicism and served as an advisor and diplomat to the Kingdom of Cyprus, the Papacy and the Republic of Venice. He played a prominent role in negotiations to end to the East–West schism of the churches and launch a general crusade against the Ottoman Turks.
He was married three times: first before 1363 to Maria Kantakouzene, a daughter of the Emperor Matthew Kantakouzenos; second around 1367 to Maria de Mimars, a Cypriot noblewoman; and third in 1372 or 1373 to Lucie, noblewoman of Frankish Greece.