Isabella Skinner Clarke–Keer (née Clarke) (29 October 1842 – 30 July 1926) was a British pharmacist and pioneer of women in pharmacy.

Her father, Edward Clarke (born c.1805), was a clerk at the time of her birth, but recorded as a solicitor in the 1861 census.

Annie Neve, who later served her apprenticeship with Isabella, described “a large family of happy, busy women.”[2] Clarke passed the Pharmaceutical Society of Great Britain Preliminary Examination in 1874, coming 23rd out of 355 candidates, 186 of whom failed.

[7] They had met when they were both students at Dr Muter's School of Pharmacy in Kennington, passing the Pharmaceutical Society Major exam on the same day as each other, with consecutive numbered certificates.

In spite of her professional achievements, she and other women employees such as Margaret Buchanan were not permitted to work visibly in the shop.

[2] After his death, she began to take in boarders, later described as a Home for Students, and also ran a shorthand and typing business in Victoria Street.

[9] In spite of Robert Hampson's campaign, the conclusion was apparently reached by some Council members "to avoid further agitation", rather than through a comprehensive belief in equal rights.

[2] In tributes after her death, Margaret Buchanan, her employee and her successor as President of the Association of Women Pharmacists explained that “her indomitable energy and savoir-faire carried her through many an awkward situation, which she in after years would describe with great glee.”[6] Annie Neve, who served her apprenticeship with Clarke-Keer, was equally appreciative of her mentor: “The initiative, energy, moral courage, and enthusiasm for the advancement of pharmacy and for the betterment of the lot of all who toil and suffer, which she so conspicuously displayed during a long and beneficent life were a heartening and ennobling example to all who came within the sphere of her influence.”[2] In 2019 she was added to the Oxford Dictionary of National Biography.