Mauritius was completed with an internal degaussing system which induced severe corrosion to the ship's fire main (made of copper); this major defect, which rendered her unfit for action, required refits, first at Simonstown, later at Singapore, and finally at Plymouth.

The future Admiral of the Fleet Henry Leach served as a midshipman aboard Mauritius during this time.

In June 1944 she covered the landings in Normandy as part of Force D off Sword Beach, then carried out offensive patrols of the Brittany coast in August to mop up the remnants of the German shipping in the area.

After this she returned to the Home Fleet, covering the carrier raids along the Norwegian coast and making anti-shipping strikes.

The years 1949 to 1951 were spent on the East Indies Station with the 4th Cruiser Squadron until she returned to Chatham on 18 December 1951.