HMS Dauntless was completed with a large hanger under her bridge, which she retained until 1920. In 1919 HMS Dauntless went to the Baltic, and was then employed on detached service in the West Indies, followed by the Atlantic Fleet 1st Light Cruiser Squadron for the following five years. After the Empire Cruise of 1923/24 she went to the Mediterranean for a few years with the 1st Cruiser Squadron. In May 1928 Dauntless was recommissioned and left the U.K. for the America and West Indies Station. In July the cruiser was badly damaged by grounding off Halifax, Nova Scotia, Canada. The engine room and one boiler room being breached, not until all guns, torpedo tubes and much other equipment was removed could the ship be re-floated and towed off by the cruiser HMS Despatch, and tugs. During 1929 repairs were carried out to the damaged hull and Dauntless was reduced to reserve. In 1930 the cruiser was transferred back to the America and West Indies Station. During 1931-1933 Dauntless served with the South American Division. In 1934 Dauntless relieved the cruiser HMS Curlew in the Mediterranean and served with the 3rd Cruiser Squadron. In 1935 the cruiser left the squadron for U.K. to be paid off into reserve.

In 1939 HMS Dauntless was recommissioned to join the 9th Cruiser Squadron with the South Atlantic Command. In December, the squadron was transferred to the China Station. In March 1940 while in the Indian Ocean HMS Dauntless was a unit of the British Malaya Force tasked to keep watch on German merchant ships in the Dutch East Indies harbours, she operated mainly off Batavia. On 15 June 1941 HMS Dauntless collided with the cruiser HMS Emerald off Malacca and required repairing at Singapore. On August 15th the repairs were completed. In February 1942 HMS Dauntless arrived at Portsmouth for a refit. Following this refit in August she was transferred to the Eastern Fleet. In November the cruiser was docked in the Selborne dry dock at Simonstown, South Africa. In January 1943 Dauntless was floated out of the dry dock. Her remaining service was in the capacity of a training ship. In February 1945 the old cruiser was reduced to reserve. Sold to be broken up for scrap on 13 February 1946. In April 1946 Dauntless was eventually broken up for scrap at T.W. Ward, Inverkeithing.