| Official Name: | Alton Bay, New Hampshire |
| Settlement Type: | Unincorporated community |
| Pushpin Map: | New Hampshire#USA |
| Pushpin Label: | Alton Bay |
| Pushpin Label Position: | bottom |
| Pushpin Relief: | yes |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | New Hampshire |
| Subdivision Type2: | County |
| Subdivision Name2: | Belknap |
| Subdivision Type3: | Town |
| Subdivision Name3: | Alton |
| Timezone: | Eastern (EST) |
| Utc Offset: | -5 |
| Timezone Dst: | EDT |
| Utc Offset Dst: | -4 |
| Elevation Ft: | 512 |
| Coordinates: | 43.47°N -71.2342°W |
| Postal Code Type: | ZIP code |
| Postal Code: | 03810 |
| Area Code: | 603 |
| Blank Name: | GNIS feature ID |
| Blank Info: | 865227 |
Alton Bay is an unincorporated community in the town of Alton in Belknap County, New Hampshire, United States, and is located on Alton Bay, a 4miles cove of Lake Winnipesaukee which forms the southernmost point on the lake. The village is part of the Lakes Region, a popular resort area of the state.
Alton Bay is located at the intersection of New Hampshire Route 11 and Route 28A, north of the center of Alton. Route 11 is an east-west highway that crosses the entire state of New Hampshire, connecting Laconia to the west and Rochester to the east. Route 28A is a local highway that joins Route 28 4miles north of Alton Bay.
In 1851, the village became the terminus of the Cochecho Railroad from Dover.[1] The rail line became the Lake Shore Railroad in 1890, continuing west to Lakeport in Laconia. It was in operation until 1935. The MS Mount Washington and its predecessor ships on Lake Winnipesaukee have made Alton Bay a stop since 1872.
Alton Bay is home to the Alton Bay Christian Conference Center, a Christian retreat center and campground organized in 1863 as the Second Advent Camp Meeting, and incorporated as the Alton Bay Camp Meeting Association in 1876. It continues its year-round ministry by hosting retreat groups, summer camps, concerts, speakers, and summer residents, who live there and participate in the services of the Association.[2]
The village has a separate ZIP code (03810) from the rest of the town of Alton.