A subject information obtaining apparatus includes a light source that emits light, a photoacoustic wave reception unit that receives a photoacoustic wave generated when the light is radiated onto a subject and that outputs a photoacoustic signal, an acoustic wave transmission unit that transmits an acoustic wave to the subject, an echo reception unit that receives an echo of the acoustic wave and that outputs an echo signal, and a signal processing unit that obtains pieces of optical characteristic information regarding the subject on the basis of the photoacoustic signal and pieces of morphological information regarding the subject on the basis of the echo signal. The signal processing unit obtains similarity between the pieces of morphological information, and, if the similarity is equal to or higher than a certain value, combines the pieces of optical characteristic information corresponding to the pieces of morphological information.
