1918 is a year in the 20th century.
- Tuesday, January 8: Evelyn Dall is born in The Bronx, New York
- Monday, November 11: World War I ends. November 11 was celebrated as Armistice Day, and in 1954 became known as Veterans' Day. As such, Friday, November 11, 1955, was a day off for Hill Valley students.
- Date Unknown: The Von Braun family, in Hill Valley for ten years, had changed its name to the more American sounding "Brown", a few years before Emmett Brown was born.
- Date Unknown: Cannons from World War I were brought back after 1918 to the Hill Valley Courthouse lawn. They were moved sometime between 1955 and 1985.