The Apple A8 is a 64-bit ARM-based system on a chip (SoC) designed by Apple Inc. It first appeared in the iPhone 6 and iPhone 6 Plus, which were introduced on September 9, 2014. Apple states that it has 25% more CPU performance and 50% more graphics performance while drawing only 50% of the power of its predecessor, the Apple A7. The latest software updates for the 1.1GHz and 1.4GHz variants systems using this chip are iOS 12.5.7, released on January 23, 2023 as they were discontinued with the release of iOS 13 in 2019, and 1.5 GHz variant for the iPad Mini 4 is iPadOS 15.8.2, released on March 5, 2024 as it was discontinued with the release of iPadOS 16 in 2022, while updates for the 1.5 GHz variant continue for Apple TV HD. The A8 chip was discontinued on October 18, 2022, following the discontinuation of the Apple TV HD.

In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, address buses, or data buses of that size. A computer that uses such a processor is a 64-bit computer.