Sensorineural hearing loss (SNHL) is a common clinical side effect resulted from the overusing of aminoglycoside antibacterial drugs, such as gentamicin. Oxidative stress is recently evidenced to be an important inducer for SNHL, which is reported to be associated with the knockdown of connexin-43. MiR-106a is recently found as a regulator of connexin-43. The present study aims to investigate whether miR-106a is a vital mediator in the development of SNHL. Firstly, upregulated miR-106a was observed in the peripheral blood sample of SNHL patients. Glucose oxidase (GO) was utilized to induce oxidative injury in isolated rat cochlear marginal cells (MCs), followed by introducing the miR-106a inhibitor. We found that the declined proliferation ability, increased apoptosis, and activated oxidative stress in GO-stimulated MCs were dramatically abolished by the miR-106a inhibitor, accompanied by the upregulation of connexin-43. The targeting correlation between miR-106a and connexin-43 was predicted and confirmed by the dual luciferase gene reporter assay. Furthermore, the regulatory effect of miR-106a inhibitor against the proliferation, apoptosis, and oxidative stress in GO-treated MCs were dramatically abolished by the knockdown of connexin-43. Gentamicin was utilized to establish the SNHL model in rats, followed by the treatments of antagomir-106a and antagomir-106a combined with carbenoxolone, an inhibitor of connexin-43. The alleviated pathological state, reduced apoptosis, and ameliorated oxidative stress in cochlea tissues were observed in antagomir-106a treated SNHL rats, which were dramatically reversed by the co-administration of carbenoxolone. Collectively, miR-106a facilitated the SNHL induced by oxidative stress via targeting connexin-43.