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.

Telecommuters are a relatively large percentage of the workforce: 8.41% 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.

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.

Compared to the rest of the country, citizens of Marathon spend much less time in their cars: on average, their commute to work is only 14.94 minutes. This also means that noise and pollution levels in the city are less than they would otherwise be.

Marathon is a small city, and as such doesn't have a public transit system that people use to get to and from their jobs every day.

The overall education level of Marathon citizens is substantially higher than the typical US community, as 29.94% of adults in Marathon have at least a bachelor's degree, and the average American community has 21.84%.

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.