'weightlifter' is a compound of 'weight' + 'lifter'; 'weight' originates from Old English 'wiht' (from Proto-Germanic '*wihti-'), where the root meant 'weight' or 'heaviness'. 'lift' comes from Old Norse 'lypta'/'lyfta' meaning 'to raise', and the agentive suffix '-er' formed 'lifter'.

'weight' changed from Old English 'wiht' to Middle English 'weighte' and eventually to modern English 'weight'. 'lift' developed from Old Norse 'lypta' into Middle English forms like 'liften'/'lift'; adding '-er' produced 'lifter'. The compound 'weightlifter' arose in modern English (late 19th–early 20th century) with the formalization of the sport of weightlifting.

Initially it literally combined 'weight' and 'lifter' to mean 'one who lifts weights'; over time it became the established term specifically for athletes who compete in or practise the sport of weightlifting.