The dude's name is in the title – of course he's the protagonist. But wait! you may say. Why so hasty, Shmoop? Watson is the first-person narrator of all of Holmes's adventures in this story collection. Why isn't he the protagonist? Watson does control the way these stories are told, but they're all stories about Holmes. Witness the fact that we never see anything more of Watson's home life than what's interrupted as he's being called away from his wife and home to help solve cool crimes with his detective pal. Holmes is the driving force behind all of these tales, and thus is definitely our protagonist.