Frances Elizabeth Deacon (née Potter) (1837–1930) was an English chemist and druggist who was the first woman to qualify after the 1868 Pharmacy Act, which made registration with the Pharmaceutical Society of Great Britain (PSGB) compulsory in order to work as a pharmacist.

Fanny married Abraham Deacon (1828–1911), a widower, in the Independent Chapel in neighbouring Kibworth Harcourt on 23 September 1875 when he was aged 46 and she was 37.

[6] He opened his post office also on Wolsey Lane in Fleckney, probably in the 1880s, and Fanny worked in the same building as a Chemist & Druggist.

Abraham died on 16 February 1911, but Fanny is still listed as a Chemist & Druggist in the census of that year, in spite of her age of 73, with Harriet her step-daughter living with her.

As the result of a public vote,[7] on 16 June 2022, a commemorative green plaque was unveiled to Fanny Deacon in Wolsey Lane, Fleckney, where she lived and ran her own business.