Chelsea is a medium-sized coastal city (i.e. on the ocean, a bay, or inlet) located in the state of Massachusetts. With a population of 38,637 people and nine associated neighborhoods, Chelsea is the 40th largest community in Massachusetts. Chelsea has an unusually large stock of pre-World War II architecture, making it one of the older and more historic cities.

Housing costs in Chelsea 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 Chelsea has more people living here who work in computers and math than 95% of the places in the US.

A relatively large number of people in Chelsea telecommute to their jobs. Overall, about 8.15% of the workforce works from home. While this may seem like a small number, as a fraction of the total workforce it ranks among the highest in the country. 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.

Chelsea 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. Such areas are often places that visitors and locals go for waterfront activities or taking in the scenery.

One downside of living in Chelsea, however, is that residents on average have to contend with a long commute, spending on average 33.82 minutes every day commuting to work. It is, however, a pedestrian-friendly city. Many of its neighborhoods are dense enough and have amenities close enough together that people find it feasible to get around on foot. In addition, local public transit is widely used. For those who would prefer to avoid driving entirely and leave their car at home, it may be an option to use the transit instead.

Although the majority of commuting trips in the city are by private automobile, Chelsea is somewhat unusual for a city of its size for having a substantial number of people who use public transportation. For a lot of people, the bus helps to get to and from their jobs every morning, which benefits everyone in the Chelsea area by reducing both traffic and air pollution.

The education level of Chelsea citizens is a little higher than the average for US cities and towns: 21.61% of adults in Chelsea have at least a bachelor's degree.

The per capita income in Chelsea in 2022 was $30,454, which is low income relative to Massachusetts, and middle income relative to the rest of the US. This equates to an annual income of $121,816 for a family of four. However, Chelsea contains both very wealthy and poor people as well.

Chelsea is an extremely ethnically-diverse city. The people who call Chelsea home describe themselves as belonging to a variety of racial and ethnic groups. People of Hispanic or Latino origin are the most prevalent group in Chelsea, accounting for 67.42% of the city’s residents (people of Hispanic or Latino origin can be of any race). The greatest number of Chelsea residents report their race to be White, followed by Black or African-American. Important ancestries of people in Chelsea include Italian, Irish, English, French Canadian, and German.

Foreign born people are also an important part of Chelsea's cultural character, accounting for 47.02% of the city’s population.

The most common language spoken in Chelsea is Spanish. Other important languages spoken here include English and Portuguese.