An automatic transmission for a hybrid vehicle, includes: an input shaft (AE) driven by the heat engine; an output wheel, ring gear or pinion (RCPS); a stationary element (ES), such as a casing; an electric motor (ME) in which the stator (ST) is rigidly connected to the stationary element (ES); and at least first, second and third members for selective torque transmission (C13; C234; C12-E2), which can be engaged or activated selectively in order to establish different transmission ratios. The automatic transmission also includes a single Ravigneaux double planetary gear set (TPR) in which the functional elements that make up same are arranged in two stages of planetary gear sets (ET1 and ET2) connected by the aforementioned members to the input shaft (AE), to the rotor (RO) of the electric motor (ME) and to the stationary element (ES).