Abstract: An underwater electric connector includes two elements (1,9) which may be coupled end to end and which are each equipped with a cylindrical cavity and a set of contact pieces (17, 20). One of the elements (1) is equipped with a device for injecting an insulating fluid under pressure. Housings (2,8) of the elements have end pieces (11,10) which may be fitted one onto the other. Each set of contact pieces is secured on the element (1,9) which carries it. A cylindrical pin (22) bears two groups (24,25) of contact pieces connected electrically by twos from one group (24) to the other (25), and is equipped with a head (26,23) which seals the cylindrical cavity (19) of the second element (9) when the pin is completely inserted. Devices for gripping (27) and displacement (28) are provided in the first element to secure the pin in the position at which its contacts (24,25) are opposite the contact pieces of the two sets (17,20) of contacts.