The evangelists are traditionally symbolized by the four animals of Revelation 4:7-8, with Luke as the "calf." A small tympanum at St. Marks in Venice pictures a literal calf among the four, but almost always the animal shown is a full-grown ox, often with the wings specified in Revelation (example). Normally a literal depiction of an ox suffices, with or without wings, but in one fresco in South Tyrol Luke is represented by an ox-headed winged man holding a stand with two books.
In the second millenium we see portraits of Luke simply as a human figure, with the ox often added as an attribute, as in the first image at right and this portrait by Cimabue.
The Cimabue shows Luke at a writing table penning a phrase from his gospel, and the books in the South Tyrol fresco surely refer to that same work. Many other portraits show him either writing in a book or holding a book or scroll (example of scroll), and the mosaic in the second picture at right also gives him a basket of scrolls, an emblem from classical times denoting a philosopher.
A separate tradition holds that Luke made a painting of the Virgin and Child. (The first picture on the right has an angel holding up the completed painting.) Molanus (271) traces this story to Theodorus Lector's 6th-century Historia Ecclesiastica. Theodorus said the painting was sent by the Empress Eudoxia from Jerusalem to her daughter Pulcheria in Constantinople (see col. 166). Many images said to be copies of Luke's painting have been made through the years, as well as many images of Luke at his easel with the Virgin and Child sitting for him as in this fresco by Vasari. This tradition led to the adoption of Luke as patron saint of artists. In the Vasari the saint is made to look like a contemporary painter, and a painting of the same era conversely presents the artist as St. Luke.
In Rome's Santa Maria Maggiore a painting of the Virgin and Child called Salus Populi Romani ("The Health of the Roman People") is claimed to have been made by Luke, and the church even has a painting of Luke making the painting.
Annibale Carracci used a palette with brushes as an attribute for the saint in The Virgin Appears to Saints Luke and Catherine.
St. Luke the Evangelist has been assumed to be "Luke, the most dear physician" of Colossians 4:14. Molanus (ibid.) tells of artists who have placed small vases that he presumes to be for medicaments in pictures of Luke's studio. I have seen a few such images, though with only one small vase in each (example).
With the exception of the latter example, St. Luke is consistently shown bearded. He also usually has a full head of hair, though exceptions include the first image at right and an odd portrayal with a tonsure in Cefalù Cathedral.
Prepared in 2014 by Richard Stracke, Emeritus Professor of English, Augusta University