The Samsung Galaxy Z Fold 3 is a foldable smartphone that is part of the Samsung Galaxy Z series. It was revealed by Samsung Electronics on August 11, 2021 at the Samsung Unpacked event alongside the Z Flip 3. It is the successor to the Samsung Galaxy Z Fold 2.

A foldable smartphone is a smartphone with a folding form factor. It is reminiscent of the clamshell design of many earlier feature phones. Some variants of the concept use multiple touchscreen panels on a hinge, while other designs utilise a flexible display. Concepts of such devices date back as early as Nokia's "Morph" concept in 2008, and a concept presented by Samsung Electronics in 2013, while the first commercially available folding smartphones with OLED displays began to emerge in November 2018.