[Problem] To develop a polarizing element exhibiting excellent polarizing properties and high durability. [Solution] A polarizing element containing a polyvinyl alcohol resin or a derivative thereof, and a dichroic dye, and formed from a stretched film, wherein at least one of the dichroic dyes is characterized by being an azo compound represented by formula (1) in the form of a free acid, or a salt of said azo compound. (In the formula, A represents a phenyl group having at least one carboxyl group functioning as a substituent.)