Population of the Canton-Massillon, OH MSA: In 2000, Canton-Massillon, OH MSA had a household population of 397,635 – 205,562 (52 percent) females and 192,073 (48 percent) males. The median age was 38.3 years. Twenty-six percent of the population were under 18 years and 15 percent were 65 years and older.(2)