Mentone is located at 34°4'10" North, 117°8'0" West (34.069722, -117.133611).
According to the United States Census Bureau, the city has a total area of 6.24 mi2 (16.17 km2). 6.23 mi2 (16.13 km2) of it is land and 0.01 mi2 (0.04 km2) of it is covered by water. The total area is 0.23% water.
Mentone is located in the Pacific Standard Time (PST) timezone, GMT-08:00. It observes Daylight Saving Time (DST).