Maryville is a city and county seat of Nodaway County, Missouri, United States. As of the 2010 census, the city population was 11,972. Maryville is home to Northwest Missouri State University, Northwest Technical School, and the Missouri Academy of Science, Mathematics and Computing.Maryville is the second largest city wholly within the boundaries of the 1836 Platte Purchase which expanded Missouri's borders into former Indian Territory in northwest Missouri.