Sir Joseph Banks, 1st Baronet, GCB, FRS (24 February [O.S. 13 February] 1743 – 19 June 1820) was an English naturalist, botanist, and patron of the natural sciences.

Banks made his name on the 1766 natural-history expedition to Newfoundland and Labrador. He took part in Captain James Cook's first great voyage (1768–1771), visiting Brazil, Tahiti, and after 6 months in New Zealand, Australia, returning to immediate fame. He held the position of president of the Royal Society for over 41 years. He advised King George III on the Royal Botanic Gardens, Kew, sending botanists around the world to collect plants, he made Kew the world's leading botanical garden. He is credited for bringing 30,000 plant specimens home with him; amongst them, he was the first European to document 1,400.

Banks advocated British settlement in New South Wales and the colonisation of Australia, as well as the establishment of Botany Bay as a place for the reception of convicts, and advised the British government on all Australian matters. He is credited with introducing the eucalyptus, acacia, and the genus named after him, Banksia, to the Western world. Around 80 species of plants bear his name. He was the leading founder of the African Association and a member of the Society of Dilettanti, which helped to establish the Royal Academy.

Banks was born in Argyll Street, Soho, London, the son of William Banks, a wealthy Lincolnshire country squire and member of the House of Commons, and his wife Sarah, daughter of William Bate. He was baptised at St James's Church, Piccadilly, on 20 February 1743, Old Style. He had a younger sister, Sarah Sophia Banks, born in 1744.

Banks was educated at Harrow School from the age of nine and then at Eton College from 1756; the boys with whom he attended the school included his future shipmate Constantine Phipps.

As a boy, Banks enjoyed exploring the Lincolnshire countryside and developed a keen interest in nature, history, and botany. When he was 17, he was inoculated with smallpox, but he became ill and did not return to school. In late 1760, he was enrolled as a gentleman-commoner at the University of Oxford. At Oxford, he matriculated at Christ Church, where his studies were largely focussed on natural history rather than the classical curriculum. Determined to receive botanical instruction, he paid the Cambridge botanist Israel Lyons to deliver a series of lectures at Oxford in 1764.

Banks left Oxford for Chelsea in December 1763. He continued to attend the university until 1764, but left that year without taking a degree. His father had died in 1761, so when Banks reached the age of 21, he inherited the large estate of Revesby Abbey, in Lincolnshire, becoming the local squire and magistrate, and dividing his time between Lincolnshire and London. From his mother's house in Chelsea, he kept up his interest in science by attending the Chelsea Physic Garden of the Worshipful Society of Apothecaries and the British Museum, where he met the Swedish naturalist Daniel Solander. He began to make friends among the scientific men of his day and to correspond with Carl Linnaeus, whom he came to know through Solander. As Banks's influence increased, he became an adviser to King George III and urged the monarch to support voyages of discovery to new lands, hoping to indulge his own interest in botany. He became a Freemason sometime before 1769.

In 1766, Banks was elected to the Royal Society, and in the same year, at 23, he went with Phipps aboard the frigate HMS Niger to Newfoundland and Labrador with a view to studying their natural history. He made his name by publishing the first Linnean descriptions of the plants and animals of Newfoundland and Labrador. Banks also documented 34 species of birds, including the great auk, which became extinct in 1844. On 7 May, he noted a large number of "penguins" swimming around the ship on the Grand Banks, and a specimen he collected in Chateau Bay, Labrador, was later identified as the great auk.