A polycarbonate diol comprising repeating units represented by the following formula (A) and a terminal hydroxy group, 60-100 mol % of the repeating units represented by the formula (A) being repeating units represented by the following formula (B) or (C). The amount of the repeating units represented by the formula (B) is 60-100 mol % based on the total amount of the repeating units represented by the formula (A). The polycarbonate diol has a terminal primary OH ratio of 95% or higher. (A) (In the formula, R represents a C2-12 divalent aliphatic or alicyclic hydrocarbon.)