Population Of New Hampshire 2025. The most populous county in new hampshire is hillsborough county, which is home to 415,427 residents. The greatest rate of growth at the start of 2023 belonged to utah (1.50%), followed by idaho (1.43%) and texas (1.34%).

The state’s population continued to grow in 2021 and 2022 because a migration gain of 18,300 was. Census data for new hampshire (pop.