A fixing support is provided for a portable electronic device, in particular in a motor vehicle. The fixing support includes a fixed base for receiving the electronic device, a retainer movably mounted on the fixed base between an idle position to place the electronic device on the fixed base and an active position to retain the electronic device on the fixed base, and a one-way lock adapted to allow the retainer to move from the idle position toward the active position, while preventing the retainer from moving from the active position toward the idle position. A motor vehicle dashboard and a motor vehicle are also provided.