Katharine Parnell (née Wood; 30 January 1846 – 5 February 1921), known before her second marriage as Katharine O'Shea and popularly as Kitty O'Shea, was an English woman of aristocratic background whose adulterous relationship with Irish nationalist Charles Stewart Parnell led to a widely publicised divorce in 1890 and his political downfall.

Although their relationship was a subject of gossip in London political circles from 1881,[4] later public knowledge of the affair in an England governed by "Victorian morality" with a "nonconformist conscience" created a huge scandal, as adultery was prohibited by the Ten Commandments.

Out of her family connection to the Liberal Party, Katharine acted as liaison between Parnell and Gladstone during negotiations prior to the introduction of the First Irish Home Rule Bill in April 1886.

Catholic Ireland felt a sense of shock when Katharine broke the vows of her previous marriage by marrying Parnell on 25 June 1891.

[4] With both his political life and his health essentially ruined, Parnell died in her arms of pneumonia[6] at the age of 45 on 6 October 1891 in Hove, less than four months after their marriage.

From her he heard a different version of the events surrounding the divorce from that which had appeared in the press, and this was to form the basis of his two books defending Parnell published in 1931 and 1938.