| Birth Date: | 25 March 1821 |
| Birth Place: | Hitchin, Hertfordshire, England |
| Death Place: | Kensington, England |
| Field: | Botany |
| Education: | King's College London |
| Known For: | Medicinal Plants (1880) |
| Awards: | Member of the Royal College of Surgeons, Fellow of the Linnean Society |
| Workplaces: | Medical School of the London Hospital, King's College London |
| Author Abbrev Bot: | Bentley |
| Signature: | Robert Bentley (botanist) signature.jpg |
Robert Bentley (25 March 1821 – 24 December 1893) was an English botanist. He is perhaps best remembered today for the four-volume Medicinal Plants, published in 1880 with Henry Trimen and containing over three hundred hand-colored plates by botanist David Blair.
Robert Bentley was born in Hitchin, Hertfordshire in 1821. While apprenticed to a pharmacist in Tunbridge Wells, he developed an interest in botany. He subsequently studied medicine at King's College London, and became a Member of the Royal College of Surgeons in 1847 and a Fellow of the Linnean Society of London in 1849.
Bentley served as botany lecturer at the Medical School of the London Hospital, and in 1859 became Professor of Botany at King's College London.
In 1874, Bentley was elected a Fellow of the Royal Pharmaceutical Society of Great Britain, and he served as joint editor of the British Pharmacopeia of 1885.
Bentley died at his home in Warwick Road, Kensington, on 24 December 1893, and was buried at Kensal Green cemetery.