493rd

493rd may refer to:


 * 493d Bombardment Group, inactive United States Army Air Force unit
 * 493d Bombardment Squadron or 93d Air Refueling Squadron (93 ARS), part of the 92d Air Refueling Wing at Fairchild Air Force Base, Washington
 * 493d Fighter Squadron (493 FS), nicknamed "The Grim Reapers", part of the 48th Fighter Wing at RAF Lakenheath, England