Emily Jane Pfeiffer (26 November 1827 – 23 January 1890, née Davis) was a Welsh poet and philanthropist.

[4] Following the financial collapse of her grandfather's bank in 1831, Pfeiffer's family lacked the resources to send her to school, but her father, Thomas Richard Davis, encouraged her to paint and write poetry.

[5] Shortly before her marriage she fell into a state of physical prostration, which threatened to become permanent, and which in part lasted for about ten years after that event.

When at last —thanks to the care of her husband— she recovered a degree of health, it was clear that this long time in which she had worked on her recovery, so far from being lost to her, assisted the development of her powers.

Together with her husband, she gathered round her a circle of distinguished literary and artistic friends, and produced her books in quick succession.

Her poems mostly formed themselves in her mind before they were committed to paper; and the manuscripts of her prose works were frequently sent to the printer, with but few corrections, as they were first written.

[4] Flowers of the night, a collection of sonnets published in 1889 after the death of her husband, dealt with themes of grief and consolation as well as the disadvantageous legal position of women.

[7] Darwin agreed that Pfeiffer's use of the term "fascination" was appropriate to describe the mechanism by which sexual selection functioned.

[11] Of the main bequest, £3,131 was given to the London School of Medicine for Women,[12] £2,000 was used to support the construction of Aberdare Hall, now part of Cardiff University,[5] and £5,000 went to Newnham College, Cambridge, paying much of the cost of its Pfeiffer Building, completed in 1893.