Olivia Langdon Clemens (November 27, 1845 – June 5, 1904) was the wife of the famous American author, Samuel Langhorne Clemens, better known as Mark Twain. Olivia Langdon was born in 1845 in Elmira, New York to Jervis Langdon and Olivia Lewis Langdon. Her childhood home from 1847 to 1862 was the building, that is now at 413 Lake Street, Elmira, NY. Jervis was a very wealthy coal businessman. The family was religious, reformist, and abolitionist. Olivia, called Livy, was educated by a combination of home tutoring and classes at Thurston’s Female Seminary and Elmira Female College. Her health was poor. She was an invalid for part of her teenage years, and she suffered from what was probably tuberculosis myelitis or Pott`s disease. She continued to have health problems throughout her life. Langdon met Samuel Clemens in December 1867 through her brother Charles. Their first date was to a reading by Charles Dickens in New York City. Clemens courted her throughout 1868, mainly by letter. She rejected his first proposal of marriage, but they became engaged two months later, in November 1868. The engagement was announced in February 1869, and in February 1870, they were married. The wedding was in Elmira, and the ceremony was performed by the Congregational ministers Joseph Twichell and Thomas K. Beecher.

In 1895 and 1896, Olivia and her daughter Clara accompanied Samuel on his around-the-world lecture tour. The next year, their daughter Susy died of spinal meningitis at age 23, a devastating blow to Olivia. The family lived in Switzerland, Austria, and England until 1902. They then returned to the United States, and lived in Riverdale, New York, arranging to move into a house in Tarrytown. Olivia’s health began getting worse. She was advised to keep a distance from her husband, and the two went months without seeing each other. By the end of 1903, doctors’ advice led the Clemens to move to Italy, for the warm climate. They resided in a villa outside of Florence. Olivia died there from heart failure in June 1904. She was buried in Woodlawn Cemetery in Elmira.