Catherine Armitage was born in Surbiton, Surrey and lived there until she was eight, when the family moved to Derbyshire. As a young adult, she took a secretarial course in Oxford, then worked at a photographic agency in London.

She moved to Bristol in 1964 to work for an interior designer, and shortly after met the artist Paul FEILER who encouraged her to undertake evening art classes. From 1967 to 1973 she completed undergraduate and postgraduate degrees at the Slade School of Fine Art.

She and Paul Feiler were married in 1970 and in 1973 moved to Kerris in Cornwall, where their twin sons were born the following year. Though apparently abstract, her work was always inspired by landscape, both in Cornwall and further afield.

In Cornwall she exhibited in various mixed shows, but also solo at the Salt House Gallery, St Ives and in the Jamieson Library of Women's History series in the 1990s. She was a long-time member of the NSA.

Her studio at Newlyn/Paul was the original Newlyn school studio of Elizabeth Adela FORBES.

Catharine Armitage exhibited in Paris, Germany and the USA in solo and mixed shows. The Waxholme series was inspired by a large outcropping of rocks in Sweden, while the Dunderet series of 2009 was based on drawings made during a trip to the Arctic Circle.