Katerina Yioulaki (Greek: Κατερίνα Γιουλάκη, born Aikaterini Yiouvarlaki (Αικατερίνη Γιουβαρλάκη) 27 March 1937 in Athens) is a Greek actress.
She studied at the Dramatic School at the National Theatre of Greece.
Her first appearance in the theater was in 1959 with Dinos Iliopoulos in the work I kiria tou kiriou (Η κυρία του κυρίου).
She felt that she marked her appearance in TV in the beginning in the 1970s in the show I kokoromiali (Η κοκορόμυαλη), in the mid-1980s with I kiria mas ( Η Κυρία μας) and in 1990–1992 in Retire (reh-tee-reh) with Giannis Dalianidis.
She was awarded the Greek Theatrical Writers' Guild Award in 1996.