Coolidge is located at (32.977105, −111.522933) at an elevation of in the northern reaches of the Sonoran Desert. According to the United States Census Bureau, the city has a total area of , all of it land. It contains no mountains and is almost entirely flat, lying in a fertile valley located just south of the Gila River. The Sacaton Mountains are visible to the west, and the Picacho Mountains are visible to the southeast.