Quintana is located at 28°55'29" North, 95°19'5" West (28.924819, -95.318331).
According to the United States Census Bureau, the town has a total area of 1.83 mi2 (4.73 km2). 0.61 mi2 (1.57 km2) of it is land and 1.22 mi2 (3.16 km2) of it is covered by water. The total area is 66.82% water.
Quintana is located in the Central Standard Time (CST) timezone, GMT-06:00. It observes Daylight Saving Time (DST).