Judith Viorst is an American writer, newspaper journalist, and psychoanalysis researcher. She is known for her humorous observational poetry and for her children's literature. This includes The Tenth Good Thing About Barney and the Alexander series of short picture books, which includes Alexander and the Terrible, Horrible, No Good, Very Bad Day (1972), which has sold over two million copies.

Alexander and the Terrible, Horrible, No Good, Very Bad Day is a 1972 ALA Notable Children's Book written by Judith Viorst and illustrated by Ray Cruz. It has also won a George G. Stone Center Recognition of Merit, a Georgia Children's Book Award, and is a Reading Rainbow book. Viorst followed this book up with three sequels, Alexander, Who Used to be Rich Last Sunday, Alexander, Who's Not Going to Move, and Alexander, Who's Trying His Best to Be the Best Boy Ever.