1983 is a year in the 20th century.
- October 30: Sergeant John Doggett leaves the Multinational Peacekeeping Force in Lebanon and the US Marine Corps. (TXF: "Within") He also got a tattoo to commemorate the Lebanon barracks bombings that killed some of his unit, the 24th Marine Amphibious Unit. (TXF: "John Doe")
- A young Samuel Hartley raises a man from the dead after a fire in Kenwood, Tennessee. (TXF: "Miracle Man")
- Fox Mulder begins his studies at Oxford University. (TXF: "Kill Switch")
- Muhaymin Daycare, a daycare center solely for nurturing Islamic children, is founded. (TXF: "The Goldberg Variation")
- Dana Scully states in 1996 that there have been twenty incidents since 1983 of "rumor panics" involving satanic cults. (TXF: "Syzygy")