Born in Cleveland, Ohio, Warshawsky was the second son of Polish immigrants and brother of Abel Warshawsky, (another prominent Ohio artist). "Xander" studied at the National Academy of Design and went to Paris in 1916. He painted Breton peasants and landscapes using flat surfaces and clear outlines, smoothly brushed surfaces and highly keyed colors. Both brothers were pacifists, serving together behind the French lines in World War I, decorating soldiers' huts with murals and organizing sports events. In recognition for this work, the French government asked Alexander and Abel to exhibit in the Luxembourg Gallery. They returned at least once a year to Cleveland. Several times they exhibited jointly.
Xander organized an exhibition in Cleveland of Post-impressionism in 1914, a controversial show, but giving Cleveland the opportunity to view modern art. Alex lived in Paris over a 25- year period, exhibiting his paintings during his frequent journeys to the U.S. He lived in Los Angeles twelve years before his death. He married Berthe, a designer of children's clothes, and had a son.