Catherine Martin was the seventh child of Samuel Mackay, a Highland crofter, and his wife Janet. Displaced by upheaval of the Highland Clearances and its consequences (including the 1846 Highland Potato Famine), the family took advantage of the possibilities afforded by the newly formed Highland and Island Emigration Society, and emigrated to Australia, arriving in 1855 and living at Naracoorte and Mt Gambier. Samuel died soon after their arrival in South Australia.
From 1867 Catherine helped her sister run a school in Mt Gambier. She developed a knowledge and love of the German language, presumably from her association with the German community in the area, and from 1872 her poems and translations of German poetry appeared in the local newspaper, the Border Watch.
In about 1875 she moved to Adelaide and struggled to support herself as a journalist. It was at this time that she met and became a friend of Catherine Helen Spence, novelist and social reformer. In 1877 she became a clerk in the Education Department.
In 1882 she married the accountant Frederick Martin and, unusually for the time, she continued her employment. However, she was discriminated against financially and failed to gain promotion. In 1885 she was dismissed.
She and her husband lived for a time at Waukaringa, north-east of Peterborough, SA, where Frederick was accountant to a gold mine. They travelled to Europe 1891-1894 and again 1904-1907. Frederick's health failed and he died in Adelaide in 1909. After his death Catherine spent long periods in Germany.
Catherine Martin's writing reflected the growing Australian nationalism of her time, and explored social issues including the role of women. Much of her writing was published anonymously or under a pseudonym; her last novel, The Incredible Journey (1923) being the first to be published under her own name.