Robert Munsch was born in Pittsburgh, Pennsylvania. He graduated from Fordham University in 1969 with a Bachelor of Arts degree in history and from Boston University in 1971 with a Master of Arts degree in anthropology.
He studied to become a Jesuit priest, but decided he would rather work with children after jobs at orphanages and daycare centers. In 1973, he received a Master of Education in Child Studies from Tufts University. In 1975 he moved to Canada to work at the preschool at the University of Guelph in Guelph, Ontario. He also taught in the Department of Family Studies at the University of Guelph as a lecturer and as an assistant professor. In Guelph he was encouraged to publish the many stories he made up for the children he worked with.
Munsch's wife delivered two stillborn babies in 1979 and 1980. Out of the tragedy, he produced one of his best-known books, Love You Forever. This book was listed fourth on the 2001 Publishers Weekly All-Time Best selling Children's Books list for paperbacks at 6,970,000 copies (not including the 1,049,000 hardcover copies). The Munsches have since become adoptive parents of Julie, Andrew and Tyya (see them all in Something Good!)
Munsch has obsessive-compulsive disorder and has also suffered from manic depression. In August 2008, Munsch suffered a stroke that affected his ability to speak in normal sentences. He has recovered enough that he is able to perform live, but has put his writing career on hold until he is fully recovered.