This paper reports on a diode-pumped picosecond passively mode-locked Yb:SSO laser. Pulses as short as 2.3 ps with a repetition rate of 53 MHz were generated, without extra negative dispersion elements. The output power achieved 1.87 W at a pump power of 11.5 W. Continuous-wave operation and wavelength tuning were examined. The CW operation achieved 3.55 W output power with a slope efficiency of 44.5%; its tuning can cover the range of 1034.0-1089.7 nm.