Amy McGrath was born in Covington, Kentucky, in 1975. As a young girl, she loved history, and she fell in love with military aviation. Every year, one of her favorite trips was to Wright-Patterson AFB to visit the USAF museum. By the time she was in 7th grade, she knew she had wanted to be a Navy or Marine Corps fighter pilot. At that point, women were not allowed to fly combat aircraft in the military.

Amy wrote letters at the age of 12 to all members of the Senate and House Armed Services Committee as well as her congressman urging them to change the law. Most of the responses, including from her congressman, were bleak, encouraging her not to pursue naval aviation but to pursue other military jobs open to her as a female, such as supply and administration. Not deterred, she earned an appointment to the US Naval Academy and in 1993, her first year there, Congress and the President rescinded the combat exclusion law allowing women to compete for coveted fighter aviation slots in all services. Amy graduated in 1997.

She completed flight school in July 1999 and reported to MCAS Miramar, San Diego, CA as an F/A-18D Hornet Weapons Systems Officer. First Lieutenant McGrath was assigned to Marine All-Weather Fighter Attack Squadron 121 "Green Knights".  In 2001, she deployed to the Middle East in support of Operation Bright Star. In 2002, Captain McGrath, call sign "Krusty" deployed to Kyrgyzstan in support of Operation Enduring Freedom where she flew over 50 combat missions in Afghanistan. In that theater of war, she became the first woman to fly in an F/A-18 in combat for the Marine Corps. In 2003, she deployed with the Green Knights to Operation Iraqi Freedom (OIF). During OIF, she flew another 30+ combat missions and dropped over 50,000 pounds of ordnance on enemy targets in Iraq. She returned from OIF to qualify as a F/A-18 air combat tactics instructor. McGrath has accrued over 2000 flight hours (350 combat flight hours), and has flown 85+ combat missions.