HMS Virulent was a V-class submarine of the Royal Navy.

She was built during the Second World War as part of the second batch (18 in number) of V-class submarines ordered on 21 May 1942.

Virulent was lent to the Hellenic Navy as Argonaftis (U15) from 29 May 1946 until 3 October 1958.

She broke adrift from the tow on 15 December 1958 and became stranded on the northern Spanish coast.

She was then found and towed by two Spanish trawlers, the frigate Hernán Cortés and the patrol boat V-18 to Pasajes on 6 January 1959.