We report on the formation of low-resistance and highly transparent indium tin oxide (ITO) ohmic contacts to p-GaN using a Sn–Ag alloy interlayer. Although the as-deposited Sn–Ag(6nm)/ITO(200nm) contacts show non-ohmic behaviors, the scheme becomes ohmic with specific contact resistance of 4.72×10 −4 Ωcm 2 and produce transmittance of ∼91% at wavelength of 460nm when annealed at 530°C. Blue light-emitting diodes (LEDs) fabricated with the Sn–Ag/ITO contacts give forward-bias voltage of 3.31V at injection current of 20mA. LEDs with the Sn–Ag/ITO contacts show the improvement of the output power by 62% (at 20mA) compared with LEDs with Ni/Au contacts.