An automatic transmission includes a single-pinion first planetary gear mechanism including a first sun gear, a first ring gear, and a first carrier that each correspond to one of first to third elements in a velocity diagram. A double-pinion second planetary gear mechanism includes a second sun gear, a second ring gear, and a second carrier that each correspond to one of fourth to sixth elements in a velocity diagram. The fifth element is connected to the second element to form a first connected body that is connected to an input shaft. A single-pinion third planetary gear mechanism includes a third sun gear, a third ring gear, and a third carrier that each correspond to one of seventh to ninth elements in a velocity diagram. The eighth element is connected to an output member, and the ninth element is connected to the third element to form a second connected body.