According to his attestation papers dated January 4, 1917, James O'Donnell, of Station Road, Mimico, was born on October 29, 1898 in Long Branch, Ontario. He was a student and listed his mother, Catherine O'Donnell, Station Road, Mimico as his next of kin. He indicated that he had no previous military experience. He was 18 years and 2 months of age. He stood 5 feet 7 1/2 inches tall. He had a mole over his right kidney and a small scar on his right breast. He had brown eyes, brown hair and fresh complexion. He was Roman Catholic.
According to the 1921 Toronto City directory he was a clerk living with his mother Catherine O'Donnell (widow Charles) on the west side of Station Road, Mimico.