Ilasco is an unincorporated community in Ralls County, Missouri, United States.
Ilasco had its start as a cement factory company town; the name Ilasco is an acronym of cement components, namely <u>i</u>ron, <u>l</u>ime, <u>a</u>luminum, <u>s</u>ilica, <u>c</u>arbon, and <u>o</u>xygen. A post office called Ilasco was established in 1919, and remained in operation until 1960.
The Ilasco Historic District was listed on the National Register of Historic Places in 2016.
Gregg Andrews, an historian, published author, and musician, was raised in Ilasco.