The purpose of this study was to investigate the effects of ultrasound-assisted marination in distilled water, kiwi, and lemon juices on the water holding capacity, pH, color (L*, a*, b*), cooking loss, and textural and sensory qualities of spent hen breast meat. In addition, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) images of the meats were determined. When compared to the marination method used alone, the water-holding capacity and drip loss of the spent hen meat samples increased as a result of ultrasound-assisted marination (P < 0.05). When compared to the other samples, the group marinated in lemon juice with ultrasonic assistance had a lower cooking loss value (P < 0.01). The results showed that the samples marinated in lemon juice had the highest L* and b* values, however, the samples marinated in lemon juice with and without ultrasound assistance had the lowest a* values. In terms of textural characteristics, the sonication treatment further reduced the shear force, even if the marination with the lemon and kiwi juices only slightly reduced it as compared to the control. The samples marinated in lemon juice with sonication support exhibited the lowest hardness value. According to DSC, the ultrasound-assisted marination process decreased the thermal denaturation temperatures of meat proteins. In terms of the SEM analysis results, it was observed that the inter-myofibrillar spaces were more evident in the chicken breast meats that underwent ultrasound-assisted marination compared to the only marination groups.