The present technology relates to a data processing apparatus and a data processing method that are able to secure good communication quality in data transmission using an LDPC code. One symbol is mapped to one of 16 signal points prescribed in 16APSK, with code bits of four bits of an LDPC code having a code length of 16200 bits and a code rate of 7/15 as one symbol. 16 signal points prescribed in 16APSK are four signal points on an inner circle and 12 signal points on an outer circle, and a radius ratio of the inner circle and the outer circle is 5.25. The present technology may be applied to, for example, a case of performing data transmission using an LDPC code.