According to the 2021 Census, there are 9,093 people in the Shire of Manjimup. Of these 50.3% are male and 49.7% female. Aboriginal and Torres Strait Islander people make up 3.3% of the population.
The median age of people in the Shire is 47 years. Children aged 0 - 14 years make up 16.2% of the population and people aged 65 years and over make up 22.8% of the population.
The most common ancestries in the Shire are English 46%, Australian 37.5%, Scottish 10.3%, Irish 9% and Italian 7.1%.
The most common responses for religion in the Shire are No Religion 49.1%, Catholic 16.1%, Anglican 11.8%, Uniting Church 2.4% and not stated 9.5%.
Of the families in the Shire, 35.3% are couple families with children, 50.2% couple families without children and 13% one parent families.