Janet Monach Patey (1 May 1842 – 28 February 1894) was an English concert and oratorio contralto.
She was born Janet Monach Whytock in London in 1842. She had a fine alto voice, which developed into a contralto, and she studied singing under J. Wass, Ciro Pinsuti and Mrs Sims Reeves (Emma Lucombe). Whytock's first appearance, as a child, was made at Birmingham.
Her first regular engagement was in 1865, in the provinces. From 1866, in which year she sang at the Worcester Festival, and married John Patey, a bass singer, she was recognized as one of the leading contraltos; and on the retirement of Helen Sainton-Dolby in 1870 Patey was without a rival whether in oratorio or in ballad music. She toured in America in 1871, sang in Paris in 1875, Australia in 1890, and New Zealand in 1891.
She died at Sheffield on 28 February 1894 and is buried in Brompton Cemetery, London. Her daughter was Ethel Patey, the artist, who under her married name, Ethel Jackson, gave a portrait of her mother to the Tate Gallery.