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.
Munsch has publicly talked about his bipolar disorder and addiction issues. 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.. On May 15, 2010 Munsch revealed that he's been diagnosed as obsessive-compulsive and manic-depressive, and that he is a recovering cocaine addict and alcoholic.
Munsch is known for his manic storytelling methods, with exaggerated expressions and acted voices. He makes up his stories in front of audiences and refines them through repeated tellings. He has said "It takes 200 tellings for a story to get good."
His stories do not have a recurring single character, instead the characters are based on the children to whom he first told the story, including his own children. He often performs at children's festivals and appears at elementary schools, sometimes unannounced. He is a bestselling author in both the United States and Canada, and has sold over 30 million books, more than any other Canadian author.
Munsch has written over 50 books, and has written several unpublished stories.
In 1999 Munsch was made a Member of the Order of Canada. On June 16, 2009, it was announced that Munsch would receive a star on Canada's Walk of Fame in Toronto. The induction ceremony was held on September 12, 2009.