The primary settlement in town, where 499 people resided at the 2020 census, is defined by the U.S. Census Bureau as the Alton census-designated place (CDP) and is centered on the intersection of New Hampshire Route 11 and New Hampshire Route 140.

The town also includes the village of Alton Bay, a long-time resort located beside Lake Winnipesaukee.

Early Alton history recounts stories of the merchants trying to convince the farmers to incorporate.

They would succeed on January 15, 1796,[5] when the community was named after Alton, a small market town in Hampshire, England.

In 1863, an Adventist group held a camp meeting at Alton Bay, which was the terminus of the Dover and Winnipiseogee Railroad.

[9] In 1872, the Boston & Maine Railroad launched at Alton Bay the steamer Mount Washington, the first side-wheeler and largest vessel on Lake Winnipesaukee.

The highest point in Alton is the north peak of Straightback Mountain, at 1,910 ft (580 m), just west of Mount Major.

New Hampshire Route 11 passes through the center of town, leading northwest along the shore of Lake Winnipesaukee to Gilford and thence to Laconia, and southeast to Rochester.

New Hampshire Route 28 also passes through the center of town, leading north to Wolfeboro and south to Pittsfield and Manchester.

[14] In the New Hampshire Senate, Alton is in the 6th District, represented by Republican James Gray.

On the Executive Council of New Hampshire, Alton is in the 1st District, represented by Republican Joseph Kenney.