To prepare a cellulose acylate film which has excellent optical properties, no foreign matter, no stain, an excellent haze value and sufficient tear strength, and to provide a polarizing plate having excellent degree of polarization and durability.

In the cellulose acylate film produced by a solution casting film-forming method, the cellulose acylate film is obtained by casting a cellulose acylate dope composition comprising a polymerizable monomer and/or a functional group-containing polymerizable monomer and a photopolymerization initiator and photopolymerizing the monomer during or after drying and has ≥10 μm and <30 μm thickness. The polarizing plate is obtained by using the cellulose acylate film.