Athanasia Gizili (Greek: Αθανασία Γκιζίλη, 14 May 1924 – 19 January 2025), better known professionally as Cathy Grey, was a Greek singer.

Grey was born in the village of Mytilinioi in Samos and had three siblings. She was adopted by the Kalaitzis family and grew up in Piraeus. Initially, she became an actress in Rita Tsakona's bands and later sang songs with Yiannis Vellas as well as other artists of the genre. Her role model was Tzimis Makoulis. Her first song, To Marazi, was recorded in 1952 and was the creation of Giorgos Mitsakis. After the success she achieved, she managed to become the first name in the biggest centers of the time and also to sing with all the great composers of her time.

Grey performed the first performances of songs by composers such as: Markos Vamvakaris, Vassilis Tsitsanis, Yiannis Papaioannou, George Mitsakis, Christos Kolokotronis, Eftychia Papagiannopoulou, Kostas Virvos, Thodoros Derveniotis, Babis Bakalis, George Zambetas and Panos Tzavellas. She collaborated with well-known artists such as: Roza Eskenazi, Stratos Payoumtzis, Stelios Kazantzidis, Grigoris Bithikotsis, Poly Panou, Mary Linda, Giota Lydia, Antonis Repanis, Stratos Dionysiou, Rita Sakellariou, Spyros Zagoraios, Panos Gavalas, George Dalaras, Eleni Vitali, Charis Alexiou, Alkistis Protopsalti, Dimitra Galani, Antonis Vardis, Stefanos Korkolis, Christos Dantis.