قصيدة نونية ابن القيم, also known as Al-Kafiya Al-Shafiya fi Al-Intisar Lil-Firqat Al-Najiya or The Poem of the Letter Nun by Ibn Al-Qayyim is an Islamic educational book that discusses the principles of Islamic beliefs and religion. The book was written by Ibn Al-Qayyim Al-Jawziyya, an Islamic scholar, in the 14th century. The book explains the fundamentals of belief according to the Salaf and clarifies them while refuting the arguments of those who oppose them. The book also covers the major innovations that were introduced by various sects and refutes them.

Ibn Al-Qayyim's methodology in writing the book is unique as he wrote it in the form of rhymed poetry with a specific rhythm and rhyme scheme. The poem consists of 5,842 verses which makes it a comprehensive encyclopedia of Islamic beliefs and principles. This book is a must-read for anyone who wants to learn about Islamic beliefs and principles.