A vehicular collision detection apparatus mounted to a vehicle comprises: a door beam that is arranged in a partitioned region partitioned between a door outer panel of a vehicle door, and a door inner panel of the vehicle door, and is displaced in accordance with a deformation of the door outer panel at the time of a vehicular collision; a cylindrical member that is arranged in the partitioned region and is compressed by the door beam at the time of the displacement of the door beam; a sealed cavity provided to the cylindrical member; a pressure sensor configured to detect a pressure fluctuation of the cavity; a deriving portion configured to derive a displacement amount and displacement velocity of the door beam, based on the pressure fluctuation detected by the pressure sensor; and a determining portion configured to determine collision particulars of the vehicle based on the displacement amount and displacement velocity of the door beam derived by the deriving portion.