'pro-populism' originates from a combination of the Latin prefix 'pro-' (from Latin 'pro', meaning 'for' or 'in favor of') and 'populism' (ultimately from Latin 'populus', meaning 'people', with the suffix '-ism' indicating a doctrine or movement).

'populism' entered modern European languages in the 19th century (e.g. French/Spanish 'populisme'/'populismo') from Latin 'populus' via various national usages; the compound 'pro-populism' is a modern English formation combining 'pro-' + 'populism' to denote support for that doctrine.

Initially the roots conveyed 'for' (pro-) and 'people' (populus); over time the combined modern term has come to mean explicit support for political movements or policies that claim to represent 'the people' often in opposition to elites.