The Secret Guide to Computers is a large, softcover book written by computer expert Russ Walter. Its various editions have been in publication for about thirty years. The latest edition is the 30th for 2008, released in September 2007. The current edition is a single volume, and weighs in at 575 pages. Previous editions were either pamphlets (very early editions) or multi-volume sets.

The Secret Guide has attracted a cult following because of Russ Walter's distinctive, hilarious writing, its low price (under $20), and the author's extreme devotion to his readers. He refers to himself as "Russy-Poo" (and instructs his readers to do the same) and gives out his phone number in the book, in case any questions come up.

The Guide covers everything relating to computers, from their hardware to their software to their history. Many people have learned to program using the Guide.