Cause of death: Alzheimer's disease
Arlene Leanore Golonka (January 23, 1936 – May 31, 2021) was an American actress. She is perhaps best known for playing Millie Hutchins on the television comedy The Andy Griffith Show and Millie Swanson on Mayberry R.F.D., and often portrayed bubbly, eccentric blondes in supporting character roles on stage, film, and television.
Source : Wikipedia