Basic Category Theory is an introductory category theory textbook. Features: It doesn't assume much, either in terms of background or mathematical maturity. It sticks to the basics. It's short. Advanced topics are omitted, leaving more space for careful explanations of the core concepts. I have used versions of this text to teach final-year undergraduate and master's-level courses at the Universities of Glasgow and Edinburgh. Samples Table of contents, note to the reader, and index Section 2.1: Adjoints: definitions and examples Section 3.1: Constructions with sets Section 4.2: The Yoneda lemma. Errata Here is a list of corrections to the printed book. If you find any others, however small, please let me know: Firstname.Lastname@ed.ac.uk. The errors have been corrected in the arXiv version. Publication and purchase The book is published by Cambridge University Press. You can find all the publication data, and buy it, at the book's CUP web page. It was published on 24 July 2014 in hardback and Kindle formats. By arrangement with CUP, a free online version is available as arXiv:1612.09375. The arXiv version is not only free; it is also freely editable. So, for instance, you can alter it to suit the needs of a course you are teaching or a device you are reading on. This page of the arXiv version tells you more. It is released under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International licence (CC NC-BY-SA 4.0).   This page was last changed on 4 December 2020. Home