Kathleen Lockhart Manning (24 October 1890 – 20 March 1951) was an American composer.
She was born on a ranch in Hollywood, California, and studied piano and composition in Paris with Moritz Moszkowski, and later with Elizabeth Jordan Eichelberger and de Sales.
She sang during the 1911-1912 season with the Hammerstein Opera Company in London and also performed in the United States.
After her husband died in 1938, she suffered from mental illness.