John Alexander Thomas Shirlow was an Australian artist.
Shirlow was born in Sunbury, Victoria, son of Robert Shirlow, a graduate of Trinity College, Dublin, who had come from Ireland and followed many occupations in the new land without much success. His mother was formerly Miss Rebecca Flanagan.
Shirlow was educated at various state schools and Scotch College, Melbourne, and went to work first at Haase Duffus and Company, printers, and then in 1889 with Sands and McDougall. He began attending evening classes at the national gallery in 1890 and continued there for five years. Towards the end of his course, influenced largely by the Rembrandt and Whistler prints at the Melbourne national gallery, he began to practise etching. His difficulties were great for he had to make his own press and correct his own mistakes. His first plate was etched in 1895 and he continued his craft until the end of his life. Most of his work is pure etching, but he did a few aquatints and mezzotints.