The present invention relates to a polyene polarizer having an order parameter (S) of about 0.9-1 inclusive and a transmittance of about 43-100% inclusive, a method for manufacturing a polyene polarizer, which can stably produce a thin polyene polarizer having a high transmittance, a high degree of polarization and a high order parameter (S) value, and a polarizing plate and an optical display device each comprising the polyene polarizer.