An in-wheel motor drive device includes an electric motor section, a speed reducer section having a speed-reduction structure using parallel shaft gears, a wheel bearing section, and a casing. The parallel shaft gears include at least one intermediate shaft each having an input-side and output-side intermediate gears, and an output shaft having a final output gear. The at least one intermediate shaft and the output shaft each have both end portions supported by rolling bearings to be rotatable. Among the rolling bearings, at least one rolling bearing arranged close to the input-side intermediate gear or a rolling bearing arranged close to the final output gear is arranged in a radially-inner-side recess portion of the gear, which is arranged close to the corresponding rolling bearing.