Mill Valley High School is a high school located in Shawnee, Kansas, and is part of the De Soto School District (USD 232). The school began classes in 2000–01. As of the 2013-2014 school year, its attendance is roughly 1,302. The school is much smaller than nearby Shawnee Mission Northwest High School and Olathe Northwest High School, because of the school board's original intent to keep class sizes small.