Assigned to USS Joseph Hewes following instruction at the Naval Reserve Midshipmen's School in Chicago, Illinois, he commanded a boat wave from that transport during the assault on Fedhala, Morocco, on 8 November 1942 during Operation Torch.

Following shakedown off Bermuda, O'Toole served as a training ship for the Fleet Sound School, Key West, Florida.

Detached on 15 July, she sailed north to Casco Bay, thence proceeded south to Norfolk, Virginia, to escort Tripoli (CVE-64) to Recife, Brazil.

Escorting Solomons (CVE-67) on the return voyage, she arrived at Norfolk, on 25 August, and continued on to New York City where she joined CortDiv 80 for transatlantic convoy duty.

Arriving at New York on 23 May, she operated off the New England coast until mid-July when she proceeded to Miami, Florida, for a brief tour as school ship.