A connector for use underwater or in a wet or severe environment comprises first and second connector parts adapted to be interengaged to establish an electrical connection. The first connector part has at least one pin, and the second connector part has at least one electrical contact for engagement by the pin when the connector parts are interengaged. The pin comprises an axially extending electrically conductive portion and an axially extending electrically insulating sleeve around said conductive portion, and the pin is supported by and projects axially forwardly from a support whereby its insulating sleeve is exposed along a longitudinally extending portion thereof to ambient conditions when the connector parts are disengaged. The connector part has a protective rigid metal sleeve member arranged to extend at least partly along the first portion of the insulating sleeve and at least partly along the second portion thereof.