HMS Chelmer was a Thornycroft Type River Class destroyer ordered by the Royal Navy under the 1903–1904 Naval Estimates.

After commissioning she was assigned to the East Coast Destroyer Flotilla of the 1st Fleet and based at Harwich.

On 27 April 1908 the Eastern Flotilla departed Harwich for live fire and night manoeuvres.

On 30 August 1912 the Admiralty directed all destroyers were to be grouped into classes designated by letters starting with the 'A'.

[3] After 30 September 1913, she was known as an E Class destroyer and had the letter 'E' painted on the hull below the bridge area and on either the fore or aft funnel.

[citation needed] In July 1914 she was on China Station based at Hong Kong tendered to HMS Triumph.