Utrillo was the son of Marie Clémentine ("Suzanne") Valadon, a well-known painter, and possibly a man named Boissy. He was adopted in 1891 by the Spanish journalist and architect Miguel Utrillo, although he continued to live with his mother and her later husbands.
He did poorly in school and in his first jobs as a bank clerk and shopworker. He began painting on the urging of his mother as a form of therapy for his alcoholism, which began when he was still a child and continued until after his marriage in 1935 to Lucie Pauwels. His greatest painting is considered to have been done before then.
He is considered one of the greatest of the 20th century's painters and his works command enormous prices. Unlike some other great artists, his genius was recognized by both the public and the art establishment while he was still productive, and he was awarded the French Cross of the Legion of Honor in 1929.