In the spring of 1937, Conyngham made her maiden cruise to ports of northern Europe, and after overhaul at Boston, Massachusetts, sailed for San Diego, California where from 22 October she conducted training exercises.

Operations along the west coast, in the Hawaiian Islands, and in the Caribbean continued until 2 April 1940, when she sailed from San Diego for Pearl Harbor, and duty with the security patrol.

Conyngham continued to patrol from Pearl Harbor through December, and after a brief overhaul at Mare Island, had escort duty between the west coast and the New Hebrides.

On 7 February she bombarded Doma Cove, and for the next 5 months, continued patrol and escort duties between bases in the South Pacific and Australia.

She continued duties in the New Guinea area, aside from a repair period in Australia in January 1944, until she sailed in March for an overhaul at San Francisco, California.

Putting into Manus for replenishment 23 December 1944, Conyngham sailed on to Hollandia to join the screen of a convoy bound for Leyte and on the landings in Lingayen Gulf.