De Courcy Lewthwaite Dewar (12 February 1878 – 24 November 1959) was a decorative metalwork designer, and member of the Glasgow Girls group of artists during the 1890/1900s.

For thirty-eight years, De Courcy taught at Glasgow School of Art, being appointed instructor of enamels by Fra Newbery.

She worked alongside fellow artists Ann Macbeth, Jessie M. King, Dorothy Carleton Smyth, Jean Delville, Peter Wylie Davidson, and Kellock Brown.

After 1926, she continued to work in a studio at her home at 15 Woodside Terrace, Glasgow[3] Some of her decorative metalwork pieces were used for illustration in Applied Design in Precious Metals, a publication by her colleague Peter Wylie Davidson.

[7] She also designed a banner for Glasgow and West of Scotland Association for Women's Suffrage in 1911 for use at the coronation of George V in London for a fee of 30 shillings.