'backbencher' originates from English, specifically formed from the compounds 'back' + 'bencher' (from 'bench'), where 'back' meant 'rear' or 'behind' and 'bench' meant 'long seat' used in legislative chambers.

'backbencher' developed as a descriptive term in 19th-century British parliamentary usage to denote MPs who literally sat on the benches at the back of the chamber; the term was later generalized to refer to MPs without ministerial office.

Initially it referred literally to where an MP sat ('those on the back benches'); over time it evolved into the broader sense of 'an MP without governmental or shadow office' and then into the informal sense of a non-prominent member of any organization.