Chatham is a town in Carroll County, New Hampshire, United States. The population was 341 at the 2020 census. It is located in the White Mountains, and except for the southeastern corner, all of Chatham is in the White Mountain National Forest. The town is home to the Cold River national forest campgrounds.

Carroll County is a county in the U.S. state of New Hampshire. As of the 2020 census, the population was 50,107, making it the third-least populous county in New Hampshire. Its county seat is Ossipee. The county was created in 1840 and organized at Ossipee from towns removed from Strafford County. It was named in honor of Charles Carroll of Carrollton, who had died in 1832, the last surviving signer of the United States Declaration of Independence.