Rear Adm. Cahill is a native of St. Albans, Vermont and a 1992 graduate of the University of Maine.
Cahill's sea tours were on USS Constellation (CV-64), USS Fitzgerald (DDG-62), USS Paul Hamilton (DDG-60) and USS Russell (DDG-59). He commanded USS Monsoon (PC-4) and USS Preble (DDG-88). His major command was on USS Bunker Hill (CG-52) where he served as the Integrated Air and Missile Warfare Commander for Carrier Strike Group NINE.
His shore tours included the Joint Staff, INDOPACOM, three tours on the Chief of Naval Operations' staff with roles in Strategy & Policy (N5SP) and Warfighting Requirements and Capabilities (N9), the Surface and Mine Warfighting Development Center and the Naval War College. He most recently served as deputy director for Resources and Acquisitions, Joint Staff (J8).
Cahill assumed the role of Commander, Carrier Strike Group FIFTEEN in June 2022.