Nerdfighter Notes are notes, usually left in books, to bring awareness to nerdfighteria. They are most often placed in copies of John Green's books at libraries and bookstores, and contain a brief introduction to nerdfighteria or vlogbrothers.

They were popularized by Kristina Horner in her 2007 Project for Awesome video: www.youtube.com/watch?v=pb35Qkb8weQ.