Olathe ( oh-LAY-thə) is the county seat of Johnson County, Kansas, United States. It is the fourth most populous city in the Kansas City Metropolitan Area and Kansas. With a 2010 population of 125,872. By 2018, the Census Bureau estimated Olathe's population had grown to 139,605.
Olathe was founded by Dr. John T. Barton in the spring of 1857. He rode to the center of Johnson County, Kansas and staked two quarter sections of land as the town site. He later described his ride to friends: "...the prairie was covered with verbena and other wild flowers. I kept thinking the land was beautiful and that I should name the town Beautiful." Purportedly, Barton asked a Shawnee interpreter how to say "Beautiful" in his native language. The interpreter responded, "Olathe."
Olathe was incorporated in 1857, and while not the first city in Johnson County, its rapid growth lead to it being named the county seat in October 1859. Rising tensions across the nation over the issue of slavery led to numerous clashes between abolitionists settlers and neighboring slave state Missouri.