Fremont County was established in 1851, named in honor of John C. Frémont, an American explorer, military officer, and politician, reflecting the westward expansionist spirit of the era.

Situated in the southwestern corner of Iowa, Fremont County is characterized by rolling hills, fertile farmland, and the meandering course of the Missouri River along its western border.

The county's geography is largely defined by the Loess Hills National Scenic Byway, showcasing unique wind-deposited soil formations that are among the thickest in the world.

Fremont County's population has experienced fluctuating trends, peaking in the late 19th century and gradually declining due to agricultural shifts and out-migration to urban centers.

Agriculture forms the cornerstone of Fremont County's economy, with corn, soybeans, and livestock production being the primary contributors to its economic base.

The Sidney Rodeo, held annually in Sidney, Iowa, is a major event attracting thousands of visitors and showcasing the county's strong ties to its agricultural and Western heritage.

Sidney, the county seat, serves as the commercial and administrative hub for the surrounding agricultural communities, providing essential services and local government functions.

The Waubonsie State Park, located within Fremont County, offers scenic hiking trails, camping facilities, and breathtaking views of the Missouri River valley, attracting outdoor enthusiasts.

Fremont County played a minor role in the Underground Railroad, with some documented instances of residents providing assistance to enslaved individuals seeking freedom.

The DeSoto National Wildlife Refuge, partially located within Fremont County, serves as a crucial migratory stopover for waterfowl and other birds, contributing to biodiversity conservation.

The Missouri River, forming the western boundary, has historically been a vital transportation route and a source of both economic opportunity and challenges, including flooding.

The demographic makeup of Fremont County is predominantly white, reflecting its historical settlement patterns and rural character.

Local traditions in Fremont County revolve around agricultural practices, community gatherings, and celebrations of rural life, such as county fairs and harvest festivals.

While not a UNESCO World Heritage site, the Loess Hills, including those in Fremont County, have been recognized for their unique geological significance and are a candidate for future designation.

Fremont County's political landscape generally leans conservative, aligning with the broader political trends observed in rural Iowa communities.