A polycarbonate copolymer including a repeating unit represented by the following formula (1) and having a copolymerization molar ratio represented by Ar2/(Ar1+Ar2) of 30 mol % or more and 47 mol % or less. In the formula (1), Ar1 is a group represented by the following formula (2a) or (2b) and Ar2 is a group represented by the following formula (3); and n is an average number of repetition and is 1.12 or more and 2.34 or less.