Device for the towing vehicle-trailer connection, comprising: - a base body associable with a trailer; - at least a first female coupling, communicating with a control line connectable to the braking system of the trailer, and at least a second female coupling, communicating with at least one additional line which acts on the parking brake of the trailer; said first and second female couplings (3, 4) being intended to receive a first and a second male coupling (5, 6) respectively, which are associable with a towing vehicle and connectable to the corresponding braking system; - wherein said first female coupling comprises a first outer tubular element and a first inner tubular element arranged one inside the other and comprises first locking means associated with said first inner tubular element; said first outer tubular element and said first inner tubular element being mutually movable between an unlocking configuration, in which said first locking means allow for the insertion/removal of the first male coupling, and a locking configuration, in which said first locking means prevent the relative movement between the first male coupling and the first female coupling; - wherein said second female coupling comprises a second outer tubular element and a second inner tubular element arranged one inside the other and comprises second locking means associated with said second inner tubular element; said second outer tubular element and said second inner tubular element being mutually movable between an unlocking configuration, in which said second locking means allow for the insertion/removal of the second male coupling, and a locking configuration, in which said second locking means prevent the relative movement between the second male coupling and the second female coupling; - at least one unlocking element locked together with said second outer tubular element and movable between a passive position and an active position in which the second outer tubular element is located in the locking configuration and in the unlocking configuration respectively, characterized in that said first female coupling is slidably movable with respect to said body between a normal operating position, in which it is substantially aligned with said second female coupling and an engagement/disengagement position, in which it protrudes with respect to said second female coupling to allow for the insertion and sequential removal of said male couplings (5, 6) with respect to the relative female couplings (3, 4), one of said body and said unlocking element being able to interact with said first outer tubular element to drag it to the relative unlocking configuration following the achievement of the active position by the unlocking element itself and the subsequent moving of said body away from the male couplings (5, 6). - a base body associable with a trailer; - at least a first female coupling, communicating with a control line connectable to the braking system of the trailer, and at least a second female coupling, communicating with at least one additional line which acts on the parking brake of the trailer; said first and second female couplings (3, 4) being intended to receive a first and a second male coupling (5, 6) respectively, which are associable with a towing vehicle and connectable to the corresponding braking system; - wherein said first female coupling comprises a first outer tubular element and a first inner tubular element arranged one inside the other and comprises first locking means associated with said first inner tubular element; said first outer tubular element and said first inner tubular element being mutually movable between an unlocking configuration, in which said first locking means allow for the insertion/removal of the first male coupling, and a locking configuration, in which said first locking means prevent the relative movement between the first male coupling and the first female coupling; - wherein said second female coupling comprises a second outer tubular element and a second inner tubular element arranged one inside the other and comprises second locking means associated with said second inner tubular element; said second outer tubular element and said second inner tubular element being mutually movable between an unlocking configuration, in which said second locking means allow for the insertion/removal of the second male coupling, and a locking configuration, in which said second locking means prevent the relative movement between the second male coupling and the second female coupling; - at least one unlocking element locked together with said second outer tubular element and movable between a passive position and an active position in which the second outer tubular element is located in the locking configuration and in the unlocking configuration respectively,