The Eastern Orthodox Church knows Margaret as Saint Marina, and celebrates her feast day on 17 July. The Greek Marina came from Antioch in Pisidia (as opposed to Antioch of Syria), but this distinction was lost in the West.

The story was summarized in the 9th-century martyrology of Rabanus Maurus, even if it was too fantastic for many clergy (it went too far even for Jacobus de Voragine, who remarks that the part where she is eaten by the dragon is to be considered apocryphal).

In 1222, the Council of Oxford added her to the list of feast days, and so her cult acquired great popularity. Many versions of the story were told in 13th-century England, in Anglo-Norman (including one ascribed to Nicholas Bozon), English, and Latin, and more than 250 churches are dedicated to her in England, most famously, St. Margaret's, Westminster, the parish church of the British Houses of Parliament in London. In art, she is usually pictured escaping from, or standing above, a dragon.

She is recognized as a saint by the Roman Catholic Church, being listed as such in the Roman Martyrology for 20 July. She was also included from the 12th to the 20th century among the saints to be commemorated wherever the Roman Rite was celebrated, but was then removed from that list because of the entirely fabulous character of the stories told of her.

Every year on Epip 23 the Coptic Orthodox church celebrates her martyrdom day, and on Hathor 23 the Coptic church celebrates the dedication of a church to her name. Saint Mary church in Cairo holds a relic believed to be Margaret's right hand, previously moved from the Angel Michael Church (modernly known as Haret Al Gawayna) following its destruction in the 13th century AD. It is displayed to the public and visitors on her feast days.