Eastport is located at 44°54'21" North, 66°59'25" West (44.906111, -66.990278).
According to the United States Census Bureau, the city has a total area of 12.06 mi2 (31.25 km2). 3.66 mi2 (9.49 km2) of it is land and 8.40 mi2 (21.76 km2) of it is covered by water. The total area is 69.64% water.
Eastport is located in the Eastern Standard Time (EST) timezone, GMT-05:00. It observes Daylight Saving Time (DST).