Alexa’s name day is April 21, the feast of Alexandra the Empress.
Churches that follow the Old (Julian) Calendar keep the same feast on May 4 of the civil calendar. See everything commemorated on April 21.
The saint behind the name
Alexandra the Empress
April 21, Holy Woman, Αλεξάνδρα η Βασίλισσα
Alexandra was, according to tradition, the wife of the emperor Diocletian. Witnessing the tortures of the Great Martyr George and the wonders wrought through him, she openly declared herself a Christian before her husband.
Also celebrating on April 21
These names share the feast, many of them other forms of the same name:
What to say on a name day
The Greek wish is Χρόνια Πολλά (Chronia Polla), “many years.” A call or a short message on the day is what people remember. See name day wishes you can send and what a name day is.