Katherine Milhous was born November 27, 1894 in Philadelphia, Pennsylvania. Her parents were named Osborn and Katherine Daly Milhous. They were Quakers and printmakers. The family moved to Pitman, New Jersey when Milhous was a little girl. A lot of Quakers lived in Pitman so the family wanted to move to be close to them. Milhous moved back to Philadelphia. She went to school at the Pennsylvania Academy of the Fine Arts and the Pennsylvania Museum of Industrial Art. She made art for magazines to pay for school. She also traveled outside of the United States with a fellowship she was given.