HMS Diadem (84)
 HMS Diadem was a Dido-class light cruiser of the Bellona subgroup of the Royal Navy. She was a modified Dido design with only four turrets but improved AA armament - aka Dido Group 2. She was built by R. and W. Hawthorn Leslie and Company Limited (Hebburn-on-Tyne) UK) with the keel being laid down on 15 December 1939.