Her daughter, Vanessa Foumberg, told The Hollywood Reporter she died of a stroke caused by high blood pressure.
"She went peacefully with both her daughters holding her hands," Foumberg said.
The actress had been on life support for three days, her friend Laurie Jacobson posted on Facebook.
"She is embedded in the tapestry that is pop culture and in our hearts always as Wednesday Addams," she said in her post.
The Addams Family, which was the first adaptation of Charles Addams' New Yorker cartoons, ran from 1964 to 1966 on ABC.
Ms Loring also appeared in the soap opera "As the World Turns" and the sitcom "The Pruitts of Southampton."
Originally born Lisa Ann DeCinces, in the Marshall Islands, she started using a stage name at age three when she started modelling.
Her work inspired later versions of the Wednesday Addams character, such as Christina Ricci's portrayal in the 1991 movie "The Addams Family" and its sequel.
The most recent actress to play Wednesday Addams is Jenna Ortega in the Netflix horror comedy hit "Wednesday". The show is one of Netflix's most watched shows of all time.
In December, Ms Ortega told Jimmy Fallon on the Tonight show she "payed homage to Lisa Loring, the first Wednesday Addams", doing "a little bit of her shuffle that she does".
John Astin, who played Gomez Addams, is the last living cast member of "The Addams Family".