'consequentialist' is formed in modern English from the adjective 'consequential' + the agentive suffix '-ist' (denoting a person who holds a particular doctrine or practice). 'Consequential' ultimately comes from Latin 'consequens'/'consequi' meaning 'to follow', while '-ist' comes via French/Latin/Greek usage meaning 'one who practices or adheres to'.

'Consequential' entered English from Late Latin/Old French roots (from Latin 'consequi' meaning 'to follow'), producing Middle English and modern English forms 'consequent'/'consequential'; the agentive suffix '-ist' was added in English usage to form 'consequentialist' to denote a follower or advocate of consequentialism.

Originally related to the sense 'following' or 'that which follows' (from Latin), the term 'consequential' evolved to mean 'having important consequences'; 'consequentialist' developed to name those who treat consequences as the basis for moral judgment and now specifically denotes that philosophical stance or its adherents.