A drive device for a construction machine includes a speed reduction unit reducing speed of rotational force output from a motor, the speed reduction unit has a gear mechanism provided in a casing and reducing the speed of the rotational force output from the motor, and an oil receiver arranged above the gear mechanism in the casing, the oil receiver forms a main storage space for storing the lubricant oil, and is arranged in the casing such that an oil passage for guiding a rising lubricant oil to the main storage space is formed between an outer surface of the oil receiver and an inner wall surface of the casing, the oil receiver is provided with an oil drain opening, the oil drain opening designed to gradually discharge the lubricant oil stored in the main storage space toward the gear mechanism through the oil drain opening.