We report on InP-based high power modified uni-traveling carrier (MUTC) photodiodes heterogeneously integrated on silicon on diamond (SOD) waveguides. Typical dark currents of MUTC photodiodes on SOD waveguides are 20 nA at - 5 V bias voltage. A 50-μm long photodiode has an internal responsivity of 1.07 A/W at 1550 nm wavelength. The bandwidths of photodiodes with active areas of 14×25 μm2, 14×50 μm2, 14×100 μm2 and 14×150 μm2 are 22 GHz, 16 GHz, 10 GHz and 7 GHz, respectively. The maximum output RF powers of 14×100 μm2 photodiodes are 13 dBm, 14.4 dBm and 15.3 dBm at 10 GHz, respectively. The maximum DC dissipated power is 0.67 W. To our knowledge, this is the first demonstration of III-V photodiodes integrated on SOD waveguides.