Dennis is a somewhat small coastal town (i.e. on the ocean, a bay, or inlet) located in the state of Massachusetts. With a population of 14,932 people and five associated neighborhoods, Dennis is the 141st largest community in Massachusetts.

Housing costs in Dennis are among some of the highest in the nation, although real estate prices here don't compare to real estate prices in the most expensive communities in Massachusetts.

Also of interest is that Dennis has more people living here who work in computers and math than 95% of the places in the US.

Telecommuters are a relatively large percentage of the workforce: 12.90% of people work from home. While this number may seem small overall, as a fraction of the total workforce it is high relative to the nation. These workers are often telecommuters who work in knowledge-based, white-collar professions. For example, Silicon Valley has large numbers of people who telecommute. Other at-home workers may be self-employed people who operate small businesses out of their homes.

Another notable thing is that Dennis is a major vacation destination. Much of the town’s population is seasonal: many people own second homes and only live there part-time, during the vacation season. The effect on the local economy is that many of the businesses are dependent on tourist dollars, and may operate only during the high season. As the vacation season ends, Dennis’s population drops significantly, such that year-round residents will notice that the city is a much quieter place to live.

It is a fairly quiet town because there are relatively few of those groups of people who have a tendency to be noisy. (Children, for example, often can't help themselves from being noisy, and being parents ourselves, we know!) Dennis has relatively few families with children living at home, and is quieter because of it. Renters and college students, for their own reasons, can also be noisy. Dennis has few renters and college students. But the biggest reason it is quieter in Dennis than in most places in America, is that there are just simply fewer people living here. If you think trees make good neighbors, Dennis may be for you.

Dennis is also nautical, which means that parts of it are somewhat historic and touch the ocean or tidal bodies of water, such as inlets and bays. Quite often, nautical areas such as these attract visitors and locals who come to enjoy the scenery and various waterfront activities.

The education level of Dennis ranks among the highest in the nation. Of the 25-and-older adult population in Dennis, 41.11% have at least a bachelor's degree. The typical US community has just 21.84% of its adults holding a bachelor's degree or graduate degree.

The per capita income in Dennis in 2022 was $52,625, which is middle income relative to Massachusetts, and wealthy relative to the rest of the US. This equates to an annual income of $210,500 for a family of four. However, Dennis contains both very wealthy and poor people as well.

The people who call Dennis home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Dennis residents report their race to be White, followed by Black or African-American. Important ancestries of people in Dennis include Irish, English, Italian, German, and French.

The most common language spoken in Dennis is English. Other important languages spoken here include Spanish and French Creole.