The novel ridge-gap waveguide (RGW) technology which uses a full metal structure has many advantages in micro/mm-wave frequencies such as low loss, broad bandwidth, low sensitivity to manufacturing errors, and easy integration with active components, etc. In this paper, a Ku-band Gysel power divider (GPD) is proposed and experimentally demonstrated based on the RGW technology for the first time, to the best of our knowledge. An RGW-to-WR62 transition is also designed and fabricated. The proposed RGW-based GPD with WR62 transitions shows low-loss equal-power division in phase with good impedance matching and isolation in the Ku band. The measured results are in good agreement with the simulations. Besides, it is shown that the proposed structure can be used as a 3-way GPD with an unequal power splitting ratio. The proposed RGW-based GPD can be extended to a 2N-way power divider which can find applications in solid-state power amplifiers, array antenna feed networks, etc.INDEX TERMS Gysel power divider (GPD), ridge gap waveguide (RGW), Ku-band, return loss, insertion loss.