A dichroic dye composition, containing at least one kind of azo dye represented by formula (I) that has a liquid crystallinity: wherein R1, R2, R3, R4, X1 and X2 each independently represent a hydrogen atom or a substituent; A1 is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted aromatic heterocyclic group; B1 is a divalent substituted or unsubstituted aromatic hydrocarbon group or a divalent substituted or unsubstituted aromatic heterocyclic group; n represents an integer of 1 to 5; and at least one of B1s represents a phenylene group having an alkyl group.