There is a great need for flexible and wearable power generators. Wire-shaped thermoelectric (TE) devices provide a solution that can convert waste heat to electricity. Here, meters-long, sewable and wearable conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) wires are fabricated based on the removal of the outer-ring PSS. The wires are sewable and exhibit a conductivity of 1433 S cm⁻¹ at room temperature, a Seebeck coefficient of 21.3 μV K⁻¹ and a power factor (PF) of 65 μW (mK²)⁻¹. The wires have a cross-sectional area of about 570 μm² and a tensile strength of about 200 MPa, and show stable electrical conductivity in air and under different temperatures. Under a temperature gradient (about 3 K) generated from hands and room temperature, a TE generator with 34 pairs of PEDOT:PSS and copper wires assembled on a fabric outputs a voltage of 2.2 mV. It shows potential for applications in wearable devices.