Al Simpson was a Weyland-Yutani Corporation employee and the senior administrator in charge of the Hadley's Hope colony on Acheron. He managed the colony throughout its history, being present from its inception until he was killed during the Xenomorph infestation that destroyed it in 2179.
Simpson was killed during the ill-fated assault on the Xenomorph Hive inside the Atmosphere Processing Plant; when one of the creatures captured him, Captain Brackett shot him dead to spare him the fate of being cocooned and impregnated.
Simpson was administrator at the Hadley's Hope colony since the very first days of the settlement. As administrator, he was in charged of the colony's day-to-day management. At some point in 2179 he received a message from Carter Burke to investigate a previously unexplored set of coordinates on LV-426's surface. Simpson passed this order on to prospectors Russ and Anne Jorden, who set out to investigate. The Jordens later contacted Simpson through the staff in the colony's operations center, seeking clarification on their rights to anything that they found, given that they were dispatched on specific Weyland-Yutani orders. Simpson was unable to provide them with a definite answer, but voiced his own opinion that, as far as he was concerned, anything that they discovered was theirs to salvage.
What the Jordens discovered was a derelict ship full of Xenomorph Eggs, triggering a Xenomorph outbreak on the moon that eventually overran the colony. As the situation became increasingly desperate, Simpson volunteered to accompany Captain Brackett and his men when they entered the main Atmosphere Processor in search of the colonists who had been abducted by the Xenomorphs. Inside, the small team was quickly set upon and decimated; Simpson was grabbed by a Warrior when he tried to flee, and Brackett shot him dead out of mercy before he could be dragged away to be a host for a Chestburster.
- Simpson voice actor Mac McDonald also voiced background characters in Alien: Isolation.
- Al Simpson was cut from the theatrical release of Aliens when the studio complained that the film was too long. The scene featuring him was later reinstated for the extended Special Edition.
- The scene featuring Simpson and Lydecker is almost identical to a scene in James Cameron's later film Terminator 2: Judgement Day: an employee flags down a supervisor in a busy office and they walk together, discussing the behavior of their employer — Weyland-Yutani in Aliens, CyberDyne Systems in Terminator 2 — before the more senior man ends their conversation with a line about their employer always responding to sensitive questions with the phrase "don't ask".