The 1965 Philippine Sea A-4 crash was a Broken Arrow incident in which a United States Navy Douglas A-4E Skyhawk attack aircraft carrying a nuclear weapon fell into the sea off Japan from the aircraft carrier USS Ticonderoga. The aircraft, pilot and weapon were never recovered.

USS Ticonderoga (CV/CVA/CVS-14) was one of 24 Essex-class aircraft carriers built during World War II for the United States Navy. The ship was the fourth US Navy ship to bear the name, and was named after the capture of Fort Ticonderoga in the American Revolutionary War. Ticonderoga was commissioned in May 1944, and served in several campaigns in the Pacific Theater of Operations, earning five battle stars. Decommissioned shortly after the end of the war, she was modernized and recommissioned in the early 1950s as an attack carrier (CVA), and then eventually became an antisubmarine carrier (CVS). She was recommissioned too late to participate in the Korean War, but was very active in the Vietnam War, earning three Navy Unit Commendations, one Meritorious Unit Commendation, and 12 battle stars.