Marion Liddell Fyfe (1 September 1897 – 26 August 1986) was a New Zealand academic, specialising in taxonomy of planarians and other flatworms, the first woman zoology lecturer at the University of Otago, and the first woman to be elected to the Council of the Royal Society Te Apārangi.

[2] She became the first female zoology lecturer at Otago in 1921, and was acting head of the department on occasion.

[3] In 1949, Fyfe became the first woman to be elected to the Council of the Royal Society Te Apārangi.

She helped first with editing of proofs for the Transactions of the Royal Society of New Zealand journal, and later became editor.

[3][7] The genus of planarians Marionfyfea was named in her honour, for "her pioneering taxonomic anatomical work on the Terricola of New Zealand".