Marathon is a somewhat small coastal city (i.e. on the ocean, a bay, or inlet) located in the state of Florida. With a population of 9,857 people and four associated neighborhoods, Marathon is the 214th largest community in Florida.

Marathon home prices are not only among the most expensive in Florida, but Marathon real estate also consistently ranks among the most expensive in America.

A relatively large number of people in Marathon telecommute to their jobs. Overall, about 8.41% 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.

Marathon 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.

Residents of the city have the good fortune of having one of the shortest daily commutes compared to the rest of the country. On average, they spend only 14.94 minutes getting to work every day.

Being a small city, Marathon does not have a public transit system used by locals to get to and from work.

In terms of college education, Marathon is substantially better educated than the typical community in the nation, which has 21.84% of the adults holding a bachelor's degree or graduate degree: 29.94% of adults in Marathon have a college degree.

The per capita income in Marathon in 2022 was $47,806, which is upper middle income relative to Florida, and wealthy relative to the rest of the US. This equates to an annual income of $191,224 for a family of four. However, Marathon contains both very wealthy and poor people as well.

Marathon is an extremely ethnically-diverse city. The people who call Marathon home describe themselves as belonging to a variety of racial and ethnic groups. The greatest number of Marathon residents report their race to be White, followed by Black or African-American. Marathon also has a sizeable Hispanic population (people of Hispanic origin can be of any race). People of Hispanic or Latino origin account for 40.40% of the city’s residents. Important ancestries of people in Marathon include Irish, German, English, Italian, and Polish.

Foreign born people are also an important part of Marathon's cultural character, accounting for 29.06% of the city’s population.

The most common language spoken in Marathon is English. Other important languages spoken here include Spanish and German/Yiddish.