Michael Vasileiou (Greek: Μιχαήλ Βασιλείου) was a Greek 19th-century merchant and benefactor. He was born in Ottoman occupied Gjirokastër, in modern Albania.
He was the brother of Alexandros Vasileiou, merchant, scholar and student of Adamantios Korais, a major figure of the Greek Enlightenment movement. Michael Vasileiou ran his trade business in Constantinople (modern Istambul), where he lived most of his life and succeeded in becoming one of the most successful businessmen among the members of the Greek community in the Ottoman capital.
He supported financially several issues of the Hermes o Logios (Greek: Λόγιος Ερμής) literary newspaper, published in Vienna as well the Greek translation of the French codex for merchants (Greek: Γαλλικός κώδιξ για εμπόρους, in 1817).
Two of his daughters (Efrosyni and Smaragda) married members of the Mellas family, which was also financially strong in the local Greek community of that time.