WKS is a spreadsheet document file created by Microsoft MS Works tool. WKS format is similar to the format used by popular Excel application but offers less features.

Works has been discontinued, but WKS files created using Works 2000 and 4.x can be viewed using Excel version 2003 and later. MS Works spreadsheet files follow standard format of rows and columns with data cells that can hold alphanumeric data along with functions or charts.