Margaret DeLuca "Peg" Klein is a former United States Navy officer who held the rank of rear admiral at the time of her retirement in March 2017.

As her final active duty assignment, Klein was named by U.S. Secretary of Defense Chuck Hagel to serve as his senior advisor for military professionalism on March 27, 2014.

In 1987, she reported to the staff of Commander, Naval Air Forces, United States Atlantic Fleet, where she was responsible for ensuring enlisted personnel readiness.

In 1988, Klein transferred to the Naval Military Personnel Command, where she served as aviation initial assignments officer and VQ detailer.

In 1991, Klein returned to VQ-3 for her department head tour, flying the E-6A as the squadron moved from Hawaii to Tinker Air Force Base in Oklahoma City.

Klein was selected as a Brookings Legislative Fellow in 1997 and served on the staff of Senator Olympia Snowe, briefing defense issues.