How many letters does the top answer for “one who drives mules.” have?

The most common answer is muleteer (8 letters).

Crossword clue: one who drives mules.

1 answer found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

muleteer 8 letters web-def

a worker who drives mules

a worker who drives mules 50% similar → muleteer, skinner

one who drives a stagecoach. 50% similar → stagecoachman

one who drives a team. 50% similar → teamster