Patricia Underhill won her first speed skating medal at the age of 14. She practically dominated Provincial and Canadian speed skating meets until her retirement in 1961. She competed in both the Canadian Outdoor Championships in 1947 and the North American Indoor Championships in 1948. Pat Underhill was the Canadian ladies outdoor speed skating champion three times. During her reign as a Canadian Champion, she also won the New York State and New England Ladies titles. Pat Underhill skated for Canada at the 1954 and 1957 World Championships in Sweden and Finland.