John Hay Cossar (2 January 1858 – 28 April 1935) was an English actor of the silent era.

He was the fifth child of Walter Cossar and his wife Kate Lyster.

In 1865 the family travelled to Canada and thence to Chicago, Illinois in the USA where John's older brother Walter Lyster Cossar later became City Editor of the Chicago Evening Journal.

In 1896, John married Fanny Cohen in Chicago.

Fanny was also an actress and the 1930 census of Los Angeles shows them living with two children, Phyllis and Raymond.