G-Shock is a line of watches manufactured by the Japanese electronics company Casio, designed to resist mechanical stress, shock and vibration. G-Shock is an abbreviation for Gravitational Shock. The watches in the G-Shock line are designed primarily for sports, military and outdoors-oriented activities; all G-Shocks have a chronograph feature, 200 metre water resistance and an alarm, with either a digital display, analogue display or a combination of analogue and digital displays. Other features such as a countdown timer, world clock, and a backlight are included in most models.

The G-Shock was conceptualized in 1981 by Casio engineer Kikuo Ibe when he bumped into a pedestrian, and the mechanical watch given to him by his father popped off of his wrist and shattered on the ground. The G-Shock then was conceived as a watch which would have “triple 10” resistance, meaning it would have a battery life of 10 years, have a water resistance of 10 bar and could survive a fall of 10 meters. A team of three individuals was selected by Ibe which was known as “team tough”. The team had assembled and tested nearly 200 prototypes but were still not able to achieve the conception criteria.

After nearly two years of development, the first G-Shock model, the DW-5000C, was released in 1983. The watch was a success, and Casio has since released many other G-Shock models, each with its own unique features and design.