Katharine Tynan (23 January 1859 – 2 April 1931) was an Irish writer, known mainly for her novels and poetry. After her marriage in 1898 to the English writer and barrister Henry Albert Hinkson (1865–1919) she usually wrote under the name Katharine Tynan Hinkson, or variations thereof. Of their three children, Pamela Hinkson (1900–1982) was also known as a writer.
Tynan was born into a large farming family in Clondalkin, County Dublin, and educated at St. Catherine's, a convent school in Drogheda. Her poetry was first published in 1878. She met and became friendly with the poet Gerard Manley Hopkins in 1886. Tynan went on to play a major part in Dublin literary circles, until she married and moved to England; later she lived at Claremorris, County Mayo when her husband was a magistrate there from 1914 until 1919.
For a while, Tynan was a close associate of William Butler Yeats (who may have proposed marriage and been rejected, around 1885), and later a correspondent of Francis Ledwidge. She is said to have written over 100 novels. Her Collected Poems appeared in 1930; she also wrote five autobiographical volumes.
Katharine Tynan Hinkson died on 2 April 1931 in Wimbledon, London, aged 72.