A medical connector (1) is provided with: a tubular connector body (2) and a lock member (3) that has an insertion hole (35) into which the connector body (2) is inserted, and that locks the connector body (2), which has been inserted into the insertion hole (35), to a female connector (9). The connector body (2) is provided with: an insertion section that is disposed on the distal side in the insertion direction of the female connector (9), and inserts into the female connector (9) and an expanding diameter section (24) that is disposed more on the proximal side than the insertion section, and increases in diameter toward the outside to a greater extent than the insertion section. The expanding diameter section (24) has an external shape defined either by an oval cross section, a convex polygon cross section, or a shape in which part of a circle is cut out in a linear fashion, in a cross-section view. The insertion hole (35) has an inner shape in which the maximum inner dimension is larger than the maximum outer dimension of the expanding diameter section (24), and in which the inner dimension that passes through the center of gravity of the insertion hole (35) is smaller than the maximum outer dimension of the expanding diameter section (24).Linvention concerne un connecteur médical (1) doté : dun corps de connecteur tubulaire (2) et dun élément de verrouillage (3), qui présente un orifice dinsertion (35) dans lequel le corps de connecteur (2) est inséré et qui verrouille le corps de connecteur (2), qui a été inséré dans lorifice dinsertion (35), avec un connecteur femelle (9). Le corps de connecteur (2) est doté : dune section dinsertion, disposée sur le côté distal, dans la direction dinsertion du connecteur femelle (9) et qui sinsère dans le connecteur femelle (9) et dune section (24) à diamètre croissant, disposée plus du côté proximal que la section dinsertion et dont le diamètre augmente vers lextérieur, dans une plus grande mesure que la section dinsertion.
