1966 was a year in the 20th century.
- Linda McFly was born.
- In the 1986B timeline, Hill Valley petitioned for exemption from state legislation to become a gated community.
- Thursday, February 24 - Billy Zane was born in Chicago Illinois.
- Sunday, June 5 - Karen Strassman (Voice Clara Clayton in LEGO Dimensions) is born in Washington D.C.
- Tuesday, July 5 - Claudia Wells was born in Kuala Lumpur, Malaysia.
- Saturday, September 17, Tracy D'Aldia (Jacuzzi Girl #2) was born
- Saturday, November 19 - Jason Scott Lee (who play Chester "Whitey" Nogura) was born in Los Angeles, California.