A false twist yarn includes dyeable polyolefin fibers characterized as being polymer alloy fibers each having a sea-island structure in which a polyolefin (A) is the sea component and a polyester (B) having cyclohexanedicarboxylic acid compolymerized therein is the island component, and in which the dispersion diameter of the island component in a fiber cross section is 30-1000 nm, wherein the number of the polymer alloy fibers is three or more, and the polymer alloy fibers have physical properties (1) and (2): (1) crimp recovery (CR) being 10-40%; and (2) hot-water dimensional change being 0.0-7.0%. The polyolefin false twist yarn is capable of developing vivid and profound colors even though the polyolefin fibers therein are light in weight.