Miss-know-it-all is the secret pen name of Nikki Maxwell, the middle-school protagonist of Rachel Renée Russell's Dork Diaries series. Nikki attends a private school on a scholarship, and in Dork Diaries 5 she joins the school newspaper and starts an advice column under that name. Her teacher-advisor, Mr. Zimmerman, suggested the pen name so readers would not track her down.

She is known for honest, funny advice on crushes, friendships and school, and for trying to answer letters thoughtfully rather than cruelly. Her humor is self-deprecating, and she can snap back quickly when rivals like MacKenz