Judith Winsor Smith was born on November 26, 1821 in Marshfield, Plymouth, Massachusetts, United States to her father, Lewis M. McLauthlen, and her mother, Polly "Mary" Judith Hathaway. Her parents were descendants of Mayflower passengers. In 1842, Judith married Silvanus Smith, a shipbuilder in East Boston. His parents, Zilpha (Drew) Smith and Jonathan Smith, were also Mayflower descendants. Sylvanus and Judith had at least six children together: two sons, Sidney Smith and Erasmus Ford Smith, and four daughters, Frances Ann Smith, Zilpha Drew Smith, Mary Hathaway Smith, and Jennie West Smith.
Judith Winsor Smith was an American women's suffrage activist, social reformer, and abolitionist. She became a suffragist in the mid nineteenth century because she perceived laws, particularly property laws, regarding women to be unjust; in 1915, at the age of 93, she was still speaking at rallies and was billed as the "world's oldest suffrage orator." In addition, Smith was an honorary vice-president of the New England Woman's Club, having joined in 1873; in 1875, persuaded by Julia Ward Howe, she founded the Home Club in East Boston, where she lived for many years. She was involved in the suffrage movement until the Nineteenth Amendment was passed in 1920, when she voted for the first time at the age of 99.