Alistair McKeon is a fictional character in the Honorverse, a series of military science fiction novels written by David Weber.
McKeon is introduced in On Basilisk Station, the first book in the mainline Honor Harrington series. He is the executive officer aboard the light cruiser HMS Fearless (CL-56) when Honor Harrington assumes command. At first, he is overcome by strong resentment directed at Harrington, feeling that he could do a better job than she could and blaming her (and himself) for the crew's poor morale. He also resents the fact that although he is 5 years older than she is, she has already commanded both a Light Attack Craft (HMLAC-113) and the Destroyer Hawkwing (DD-1213). Eventually he manages to overcome his differences with Honor, becoming one of her closest friends and later godfather to her son. He fought alongside her and the crew of Fearless against the Havenite Q-Ship Sirius at Basilisk.
After Basilisk, McKeon was promoted to the rank of Commander and given command of the destroyer HMS Troubadour, which was destroyed while defending Grayson from the Masadan battlecruiser MNS Thunder of God (also known as PNS Saladin). Alistair was then promoted out of grade to Captain of the List and assigned to command the heavy cruiser HMS Prince Adrian. While in command of this ship, and just following his promotion to Commodore, he was captured by Havenite forces and stranded with Honor on the prison planet Cerberus III. He served in Honor's ersatz military force, the Elysian Space Navy, commanding the heavy cruiser Krashnark and battle cruiser Wallenstein.
When the Elysian Space Navy returned to Manticore, Alistair was promoted to Rear Admiral and given command of a superdreadnought squadron. His flagship was the brand-new superdreadnought HMS Troubadour.
McKeon was killed aboard his flagship, HMS Intransigent, at the Battle of Manticore.