A quick-release connector for pairs of hoses or other conduits has a tubular male component the front portion of which is insertable into the front part of a tubular female component and carries one or more sealing elements which engage the internal surface of the front part. The front portion of the male component is surrounded by a ring-shaped radially deformable retaining member with a smooth conical external surface which diverges from the axis of the male component in a direction toward the rear portion. The front part of the female component has a chamber behind one or more detents with radial flanks for engagement with the maximum-diameter end of the retaining member when the latter is fully received in the chamber. An annular deforming member is mounted in two windows of the front part for axial movement between a retracted position and an extended position in which the deforming member deforms the retaining member so that the latter can bypass the detent or detents and permits extraction of the front portion of the male component from the female component. The detent or detents deform the retaining member during insertion into the chamber, and the retaining member thereupon expands to abut the flank or flanks of the detent or detents. The windows communicate with the chamber of the front part and can extend all the way to the front end face of the female component.