Born in Pine Bluff, Arkansas, to cotton broker George V. Beall and teacher Arie Beall (née Ferguson), Martha Beall Mitchell graduated from Pine Bluff High School in 1937, She attended Stephens College in Columbia, Missouri, the University of Arkansas at Fayetteville and the University of Miami, from which she received a BA in history. She worked for about a year as a teacher in Mobile, Alabama, then returned to Pine Bluff in 1945. After World War II, she began work as a secretary at the Pine Bluff Arsenal, but was soon transferred (with her boss, Brigadier General Augustin Mitchell Prentiss) to Washington, D.C., where she met Clyde Jennings, Jr. whom she married on 5 October 1946, and with whom she moved to New York City. By Jennings, she had a son, Clyde Jay Jennings (b. 2 November 1947). The couple separated on 18 May 1956 and divorced on 1 August 1957. She married John N. Mitchell on 30 December 1957. The couple had a daughter, Martha Elizabeth, nicknamed Marty (born 10 January 1961). John Mitchell met Nixon professionally, became a friend and political associate, and was appointed Attorney General after Nixon’s 1968 election to the presidency. As a result of his association with the 1972 campaign, he became associated with the growing Watergate scandal. The Mitchells separated in 1973. After the Watergate break-in, Martha Beall Mitchell began contacting reporters when her husband’s role in the scandal became known, which earned her the title, “the Mouth of the South.” Nixon was later to tell interviewer David Frost in 1977 that Martha was a distraction to John Mitchell, such that no one was minding the store, and “If it hadn’t been for Martha Mitchell, there’d have been no Watergate.”

At one point, Martha Beall Mitchell insisted she had been held against her will in a California hotel room and sedated to prevent her from making controversial phone calls to the news media. Because of her allegations, she was discredited and even abandoned by most of her family, except her son Jay. Nixon aides even leaked to the press that she had a “drinking problem”. The “Martha Mitchell effect”, in which a psychiatrist mistakenly or purposely identifies a patient’s extraordinary claims as delusions, despite their veracity, was later named after her. In 1976, in advanced stages of multiple myeloma, Mitchell slipped into a coma and died at Memorial Sloan Kettering Hospital in New York City at age 57. She is buried in the Bellwood Cemetery in Pine Bluff.