Photoacoustic imaging systems and methods that allow for the creation of three-dimensional (3D) images of a subject are described herein. The systems include one or more optical fibers attached to an ultrasound transducer. Ultrasonic waves are generated by laser light emitted from the optical fiber(s) and detected by the ultrasound transducer. 3D images are acquired by ultrasound signals from a series of adjacent scan planes or frames that are then stacked together to create 3D volume data.