Osteoarthritis is a degenerative joint disease, worldwide, and its underlying molecular mechanisms are still poorly understood. MicroRNAs are important regulators of diverse biological processes, including osteoarthritis. In this study, we showed that miR-103 was deregulated in osteoarthritis patients. We performed CCK8 and colony formation assay and found that miR-103 inhibited chondrocyte proliferation. We also found that miR-103 inhibited chondrocyte formation and maturation by RT-PCR, western blotting, and immunocytochemistry. Inhibition of miR-103 suppressed production of the catabolic factors and pro-inflammatory cytokines induced by IL-1β in chondrocytes. Finally, we found that Sox6 was a direct target of miR-103 and participated in osteoarthritis development. In summary, we demonstrated that miR-103 contributed to osteoarthritis development by directly targeting and inhibiting the expression of Sox6. Regulation of miR-103 expression in human chondrocytes may be an effective treatment for osteoarthritis.