1879History
A post office called Grain Valley has been in operation since 1879.
2000History
=== 2000 census ===
At the 2000 census there were 5,160 people.
2010History
=== 2010 census ===
In the 2010 census there were 12,854 people in 4,566 households, including 3,395 families, in the city.
2015History
The district had an enrollment of over 4000 students in 2015, up from 1659 students in 2000.
2016History
The 2016-2020 5-year American Community Survey estimates show that the median household income was $76,750 (with a margin of error of +/- $9,148) and the median family income wa...
2020History
== Demographics ==
=== 2020 census ===
The 2020 United States census counted 15,627 people, 5,109 households, and 3,656 families in Grain Valley.