He was the son of Thomas Parrish, who came from an artistic Philadelphia family, and Anne Lodge, who had studied at the Pennsylvania Academy of Fine Arts, becoming a respected portrait painter, and becoming a friend of Mary Cassatt in Paris.

[citation needed] Dillwyn Parrish studied art in Philadelphia, then attended Harvard University, where he made the acquaintance of Conrad Aiken and E. E. Cummings.

During World War I, he volunteered to drive ambulances for the American Field Service in France, but after being diagnosed with severe malnutrition he was sent back to the U.S. to recover.

In 1927, at age thirty, he married the fifteen-year-old "Gigi", and for their honeymoon the couple started out on motorcycles from his home in Claymont, Delaware, intending to drive across the country to California.

In 1929, they moved permanently to California, where a few years later, the beautiful Gigi Parrish was signed to a contract with Samuel Goldwyn's motion picture company and in 1934 she became one of the WAMPAS Baby Stars.

Dillwyn Parrish fell in love with Mary Fisher, and after encouraging her writing, helped get her culinary essays published in 1937 under the title Serve it Forth.