Tolland County is a county located in the northeastern part of the U.S. State of Connecticut. As of the 2010 census, the population was 152,691. 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.