Sideline

Sideline(s) may refer to:


 * Extended side, the geometric line that contains the side of a polygon
 * Sidelines, the lines that mark the outer boundaries of a sports field
 * Sideline (app), a smartphone app
 * Sidelines (newspaper), the student newspaper of Middle Tennessee State University
 * Sideline, a side road in the concession road system of Upper and Lower Canada
 * Side Line, a 1987 album by Onyanko Club
 * "Sidelines", a 2022 song by Phoebe Bridgers
 * Side job - an additional job in order to supplement income