Background and Purpose: Treatment of osteoarthritis (OA) pain often yields unsatisfactory results, making the search for new pain-relieving options essential. Vortioxetine, an antidepressant with a unique mechanism of action, has recently shown analgesic properties. We aimed to investigate its effects in the OA model and gain insight into the underlying molecular mechanisms. Duloxetine (a second-line drug for pain relief in OA) was studied as a reference. Experimental Approach: In the monoiodoacetate (MIA)-induced model of knee OA in rats of both sexes, pain-related behaviour was assessed in weight-bearing and von Frey tests. Antidepressants were administered orally once daily for 28 days. Gene expression of pain-related mediators (Ngf, Il-1β, Tnf-α, Bdnf, and Tac1 encoding substance P) and oxidative stress parameters were determined after completion of the treatment/behavioural testing protocol. Key results: Vortioxetine dose-dependently reduced weight-bearing asymmetry and mechanical allodynia of the paw ipsilateral to the MIA-injected knee. Duloxetine was also effective. Vortioxetine reduced the increased Ngf mRNA expression in the MIA-injected knees to the level observed in the sham-injected counterparts. It also reduced oxidative stress parameters in the affected knees, more effectively in females than in males. Duloxetine showed no effect on locally increased Ngf mRNA expression and oxidative stress. Both antidepressants decreased mRNA expression of pain-related mediators in the lumbar L3-L5 ipsilateral DRGs and spinal cords, which were upregulated in MIA-injected rats. This effect was male-specific. Conclusion and Implications: Vortioxetine may be effective against chronic pain in OA. This effect appears to be mediated, at least in part, by normalization of NGF expression in the affected joint.