HMS Scylla was a Dido-class cruiser of the Royal Navy. She was built by Scotts Shipbuilding and Engineering Company (Greenock, Scotland), with the keel being laid down on 19 April 1939. She was launched on 24 July 1940, and commissioned 12 June 1942. One of two sisters (the other was, appropriately, Charybdis, see Scylla and Charybdis), Scylla was completed with four twin QF 4.5 in Mk.III in UD MK III mountings because of a shortage of the intended QF 5.25 inch gun mountings. The forward superstructure was considerably modified to accommodate these and also to increase crew spaces. Known as the 'toothless terrors', they proved to be very good anti-aircraft ships, often leading to comparisons with their sisters armed with the heavier QF 5.25 in (133 mm) guns