The Newfoundland Royal Naval Reserve was a military reserve force founded in 1900 in what was then the Newfoundland Colony, a part of the British Empire. From 1900 to 1902, approximately 50 members of the reserve trained each winter with the North American and West Indies squadron of the Royal Navy until a steam and sail powered training ship, HMS Calypso, was provided by the United Kingdom in 1902 for local drills before at-sea training with the NA and WI squadron. The reserve had 375 members by late 1903 and then between five and six hundred reservists until the start of World War I, growing to over 1000 in 1915. 1,964 Newfoundlanders served with the Naval Reserve in World War I, suffering 192 fatalities. The Reserve disbanded in 1920-1921. Calypso, having been renamed HMS Briton, was sold as a storage hulk and was burned for salvage near Lewisporte, Newfoundland and Labrador.

HMS Calypso was a corvette of the Royal Navy and the lead ship of its namesake class. Built for distant cruising in the heyday of the British Empire, the vessel served as a warship and training vessel until 1922, when it was sold.