Tetonia is a city in Teton County, Idaho, United States, about 50 miles (80 km) northeast of Idaho Falls, Idaho (center to center) and about 425 miles (684 km) northwest of Denver, Colorado. The population was 269 at the 2010 census.
According to the United States Census Bureau, the city has a total area of 0.57 square miles (1.48 km2), all land. Tetonia is located at 43°48′50″N 111°9′35″W, in Teton County Idaho.
Tetonia was established as an agricultural town in the late 19th century, taking its name from the nearby Teton Range. Many of the businesses previously operating in Haden relocated to Tetonia following the arrival of the Union Pacific railroad.
As of the census of 2010, there were 269 people, 95 households, and 62 families residing in the city. The population density was 471.9 inhabitants per square mile (182.2/km2). There were 122 housing units at an average density of 214.0 per square mile (82.6/km2). The racial makeup of the city was 92.2% White, 0.7% Native American, 6.3% from other races, and 0.7% from two or more races. Hispanic or Latino of any race were 10.8% of the population.