Kathleen Marescaux (3 July 1868 – 14 April 1944), born Kathleen Louisa Rose Dennis, was an Irish artist, best known as a painter of botanical subjects and rural landscapes.

Kathleen Louisa Rose Dennis was born in Kilkenny, the daughter of James Benjamin Dennis and Emma Salmon Dennis.^[1] Her father was a military officer, and her mother was born in India, into an English military family.^[2]

Marescaux was best known for painting botanical subjects and rural landscapes.^[3] She first exhibited at the Royal Hibernian Academy in 1893, and continued there until 1935. Her works were also seen at the Towner Gallery in Eastbourne,^[4] and in shows with the Dublin Sketching Club, the WCSI, the Fine Art Society (London) and the Ulster Academy of Arts.^[5]

Kathleen Dennis married London-born Royal Navy officer (later Vice-Admiral) Gerald Charles Adolphe Marescaux at St. Canice's Cathedral in 1894.^[1][6] She had two sons, Geoffrey (1901-1986) and Laurence (born 1903).^[2] Kathleen Marescaux was widowed in 1920,^[7] and she died in 1944, in Kilkenny, aged 75 years. There is a collection of her papers, and another of her family's papers, in the National Library of Ireland.^[8][9]

In 2009, to mark the 400th anniversary of Kilkenny as a city, the Butler Gallery held "Kilkenny: An Artists Celebration", an exhibition featuring Kilkenny artists, including Kathleen Marescaux.^[10]

Marescaux is associated with Bonnettstown House in Kilkenny, through her son, Commander Geoffrey Marescaux de Saubruit, and through her sister, Ethel Mary Dennis Knox. A book about Bonnettstown House was published in 1989 by American photographer Andrew Bush and author Mark Haworth-Booth.^[11] The house was sold most recently in 2017.^[12]