Tolland County is a county located in the northeastern part of the U.S. State of Connecticut. As of the 2020 census, the population was 149,788. The county has a total area of 1,080 km2 (417 mi2). 1,062 km2 (410 mi2) of it is land and 18 km2 (7 mi2) of it is water. The total area is 1.66% water.