Elizabeth H. "Cissie" Sewell (born about 1893 – died after 1954) was an English-born stage actress, dancer, and ballet mistress, wife of Irish-born Canadian performer Cyril Biddulph.

[9][10] Off-stage, Sewell endorsed musical instruments,[11] and worked with playwright Noël Coward, music director Elsie April, and producer Charles B. Cochran,[12][13] especially as ballet mistress on the American and Australian productions of Bitter Sweet.

He died in World War I, in August 1918; he was a lieutenant in Princess Patricia's Canadian Light Infantry.

[21][22] In 1920, when fire broke out in the Boston hotel where she was staying, she delayed her evacuation until she rescued a photograph of her late husband, "disregard[ing] her valuable jewels, clothing and bonds".

[23] Ellis Island immigration records state that Sewell remained an unmarried widow through at least 1923.