A planetary gear device includes: a sun gear; a plurality of planet gears that mesh with the sun gear; and a baffle unit disposed in a circumferential gap between the adjacent planet gears. The baffle unit includes: a first introduction opening portion open in a radially inward direction to introduce lubricating oil, which has lubricated the sun gear and the planet gears, into the baffle unit; an end wall forming one end in an axial direction of the first introduction opening portion; a discharge opening portion to discharge lubricating oil in the baffle unit; and a guide portion disposed at a side portion of the baffle unit on a rear side in rotation direction of the sun gear, and configured to cover the first introduction opening portion in the circumferential direction and to guide the lubricating oil to an outer circumference of the adjacent planet gears.