We report on diode-pumped continuous-wave Pr-doped yttrium lithium fluoride (Pr:YLF) laser and its frequency doubling to 320 nm. The maximum output power of the 640 nm fundamental wave reached 3.44 W with a slope efficiency of about 48.3%. Using a type-I phase-matched lithium triborate (LBO) crystal as a frequency doubler, we have achieved 320 nm ultraviolet radiation with a maximum output power of 1.01 W, which is the highest power ever reported under diode pumping, to the best of our knowledge.