Provided is a polymerizable composition for an optical material including (A) isocyanates having two or more isocyanato groups, which include at least an isophorone diisocyanate, (B) at least one predetermined thiol having two or more mercapto groups, (C) an acidic phosphoric acid ester represented by General Formula (1), and (D) a tin compound represented by General Formula (2), in which the acidic phosphoric acid ester (C) is contained in an amount of 0.05 parts by weight to 0.9 parts by weight, with respect to a total of 100 parts by weight of the isocyanates (A) and the thiols (B), and the tin compound (D) is contained in such an amount that the content of tin is 0.05 parts by weight to 0.3 parts by weight, with respect to a total of 100 parts by weight of the isocyanates (A) and the thiols (B).