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An impact force probe was fabricated and tested on Solo papaya fruit at five different stages of ripeness. The probe derived force characteristics were related to fruit ripeness, firmness, and yellowing. The magnitude of the first peak of the impact force response was found to correlate with fruit firmness and inversely correlated with ripeness with correlation coefficients r = 0.894 and 0.809, respectively. Impact testing did not hasten fruit ripening and was found to be more sensitive at determining firmness of ripe fruit compared to penetrometer firmness or color measurement. However, the probe could not separate immature from mature green fruit. Fruit mass and irregularity of fruit shape did not significantly affect either the impact response or penetrometer firmness. Therefore, the impact force probe was capable of grading fruit into different stages of ripeness.