Bethany is a city in and the county seat of Harrison County, Missouri, United States. The population was 3,087 at the 2000 census.
A limestone outcropping on Big Creek on the west side of town gives its name to the Bethany Falls Limestone formation. The falls no longer exist and only a small amount is exposed. However the formation extends through Kansas City, Missouri and limestone is used extensively in buildings in that city and the formation is the basis for Subtropolis which claims to be the world's largest manmade commercial cave. The formation got its name in 1862 in a study by G.C. Broadhead who did many of the geological surveys for Missouri at the time.
Bethany is located at 40°16′0″N 94°2′2″W / 40.266667°N 94.03389°W / 40.266667; -94.03389 (40.266579, -94.034005). According to the United States Census Bureau, the city has a total area of 4.4 square miles (11.5 km²), of which, 4.4 square miles (11.5 km²) of it is land and 0.22% is water.