Who is the narrator in 3 men in a boat?

The narrator in "Three Men in a Boat" is Jerome K. Jerome himself, who tells the story from a first-person perspective. He recounts the humorous misadventures of himself and his two friends, George and Harris, as they embark on a boating trip along the River Thames. The narrative is filled with witty observations and anecdotes, reflecting Jerome's comedic style and his observations about life and human nature.