Arnold is a medium-sized city located in the state of Missouri. With a population of 20,845 people and nine associated neighborhoods, Arnold is the 34th largest community in Missouri.

Also of interest is that Arnold 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 Arnold telecommute to their jobs. Overall, about 7.34% 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.

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

The population of Arnold overall has a level of education that is slightly above the US average for all US cities and towns of 21.84%. Of adults 25 and older in Arnold, 23.17% have at least a bachelor's degree.

The per capita income in Arnold in 2022 was $35,657, which is wealthy relative to Missouri, and upper middle income relative to the rest of the US. This equates to an annual income of $142,628 for a family of four. However, Arnold contains both very wealthy and poor people as well.

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

The most common language spoken in Arnold is English. Other important languages spoken here include Polish and Serbo-Croatian.