The society was founded in 1833 as the Entomological Society of London. It had many antecedents beginning as the Society of Entomologists of London.
The foundation of the society began with a meeting of "gentlemen and friends of entomological science", held on 3 May 1833 in the British Museum convened by Nicholas Aylward Vigors with the presidency of John George Children. Those present were the Reverend Frederick William Hope, Cardale Babington, William Yarrell, John Edward Gray, James Francis Stephens, Thomas Horsfield, George Thomas Rudd and George Robert Gray. Letters of Adrian Hardy Haworth, George Bennett and John Curtis were read where they expressed their regrets to be unable to attend the meeting.
They decided that a society should be created for the promotion of the science of entomology in its various branches and it should be called the Entomological Society of London. J.G. Children, F.W. Hope, J.F. Stephens, W Yarrell and G Rudd were elected to form a committee, with G.R. Gray as secretary. J.G. Children became the first president and William Kirby (1759–1850) was made honorary president for life. The real date of the foundation of the society was more probably on 22 May 1833, when the members met in Thatched House Tavern, on St James's Street. During this meeting, George Robert Waterhouse (1810–1888) was elected librarian and curator of the insects and records. As of this meeting, foreign honorary members were elected: Johann Cristoph Friedrich Klug (1775–1856), Wilhem de Haan (1801–1855), Victor Audouin (1797–1841), Johann Ludwig Christian Gravenhorst (1777–1857), Christian Rudolph Wilhelm Wiedemann (1770–1840), Carl Eduard Hammerschmidt (1800–1874) and Alexandre Louis Lefèbvre de Cérisy (1798–1867). William Blandell Spence (1813–1900) received the task of maintaining of the relations with continental entomologists.
The society started to assemble a library, an early addition being the personal library of Adrian Hardy Haworth (1767–1833), purchased by John Obadiah Westwood (1805–1893) on behalf of the society. The insect collection also increased.
In September 1834, the society numbered 117 honorary members and 10 full members. Women were allowed membership and profited from the same rights as the men. A publication commenced in November 1834 under the title Transactions of Entomological Society of London.