SS O-16 SS O-19 SS O-20 SS O-21 SS O-24 DD-450 O'Bannon DD-415 O'Brien DD-725 O'Brien II DE-340 O'Flaherty DE-188 O'Neill DE-330 O'Reilly CL-95 Oakland DE-344 Oberrender DD Oboro DD Odake APD-71 Odum CL Oi DD Oite DD Ojashio CL Ojodo DD Okikaze DD Okinami BB-37 Oklahoma CL-91 Oklahoma City DE-417 Oliver Mitchell CVE-79 Ommaney Bay DD Onami DD-617 Ordronaux DD Oshio SS Osiris APD-35 Osmond Ingram DE-701 Osmus DE-164 Osterhaus DD Otori DE-244 Otterstetter APD-23 Overton DD-536 Owen