I always have to look this stuff up, so I decided to put it someplace easy for me to find.

15.x Sequoia

• Released October, 2024

14.x Sonoma

• Released September 26, 2023

13.x Ventura

• Released October 24, 2022

12.x Monterey

• Released October 25, 2021

11.x Big Sur

• Released November 12, 2020
• First post 10.x release.
• First release to support the new Apple Silicon architecture (M1 CPU), so this is the first release that runs on both Intel and Apple Silicon architectures.

10.15 Catalina

• Released Oct 2019

10.14 Mojave

• Released Sep 2018
• Requires certain graphics chip sets, oldest systems that will run this release are from 2012.

10.13 High Sierra

• Released Sep 2017

10.12 Sierra

• Released Sep 2016

10.11 El Capitan

• Released Sep 2015

10.10 Yosemite

• Released Oct 2014

10.9 Mavericks

• Released Oct 2013

10.8 Mountain Lion

• Released Jul 2012

10.7 Lion

• Released Jul 2011
• This is the first 64-bit only release. It supports 32-bit applications but requires a 64-bit CPU.

10.6 Snow Leopard

• Released Aug 2009
• This release requires Intel architecture CPUs.

10.5 Leopard

• Released Oct 2007
• This was the first release to support Intel CPU, also the last release to support PPC, so this is the crossover release.

10.4 Tiger

• Released Apr 2005

10.3 Panther

• Released Oct 2003

10.2 Jaguar

• Released Aug 2002

10.1 Puma

• Released Sep 2001

10.0 Cheetah

• Released Mar 2001