The invention relates to a clutch unit for a motor vehicle, comprising: a clutch, the clutch having an axially stationary, rotatable coupling element with an axially extending toothing, and an axially displaceable, rotatable mating element with an axially extending mating toothing, the mating element being displaceable into a first position and a second position; and a sensor unit, the sensor unit being disposed radially in relation to the axial extension of the toothing of the coupling element such that the sensor unit senses the toothing of the coupling element. When the mating element is in the first position and when it is in the second position, the sensor unit detects a sensor signal via which the rotational speed of the coupling element and the first position of the mating element, the second position of the mating element, or a position of the mating element between the first position and the second position can be determined. The invention also relates to a motor vehicle drive train comprising a clutch unit of this type.