There are hundreds of Enneagram books out there and as an Enneagram coach and educator I have read A LOT of them. Let me help you narrow down which ones to read next.
Enneagram Books That are Worth Your Time to Read
Let me recommend some recent reads that I found super helpful on my Enneagram journey!
The Enneagram at Work by Jim McPartlin

Use the power of the Enneagram to become a more effective, capable leader with these practical and applicable tools.
Good For: Working professionals and teams
The Enneagram for Black Liberation by ChiChi Agoro

Good For: Someone looking for collective liberation and healing (and more than just a typing system!)
A tool for Black readers, specifically Black women, to return to their truest selves in a system that seeks to dampen their self-worth and belonging.
The 9 Types of Leadership by Beatrice Chestnut

Good For: Leaders who want to dive deeper into their type and subtype
Harness your unique Enneagram type to create more effective relationships, feel happier at the office, and utilize your strengths (and weaknesses!) as a leader.
My Enneagram by Abbey Howe

Good For: Book clubs and journaling enthusiasts
Discover how the Enneagram is your key to deeper self-awareness, stronger relationships, and burnout-free growth. (I had to put my own book in here, guys. I’m obsessed with it 😉 ) Learn more about it here!
The Honest Enneagram by SaraJane Case

Good For: Enneagram beginners and gentle questioners
Beginner’s book approaches the Enneagram through the H.O.N.E.S.T method. Written by the creator of the viral Enneagram and Coffee Instagram account.
Illustrated Enneagram by Deanna Talwalkar

Good For: Visual learners
A simple, illustrated guide to understand the basics of the Enneagram and all 9 types.
The Road Back to You by Ian Morgan Cron and Suzanne Stabile

Good For: Fans of story-based books about self-awareness
A practical, comprehensive way to find your Enneagram type and explore the spiritual connections associated with it.
The following video mentions a couple more!
Happy Discovering! If you want some book recommendations according to your Enneagram type, this blog post suggests one for each.
