Lewisville is located at 33°2'45" North, 96°59'36" West (33.046111, -96.993611).
According to the United States Census Bureau, the city has a total area of 42.34 mi2 (109.65 km2). 36.79 mi2 (95.30 km2) of it is land and 5.54 mi2 (14.36 km2) of it is covered by water. The total area is 13.09% water.
Lewisville is located in the Central Standard Time (CST) timezone, GMT-06:00. It observes Daylight Saving Time (DST).