Hertfordshire Natural History Society was founded in 1875 in Watford. From that date to the present, there has been a continuous pursuit of natural history study across the County.

In its early years, it inherited the work of a number of Victorian naturalists, especially botanists and geologists. The Revd. R. H. Webb, who had co-authored the first Hertfordshire "Flora" in 1849 with W. H. Coleman, survived just long enough to be a founder member of the Society. Bird and mammal studies benefited in the early days from people like H. Harpur Crewe, A. F. Crossman and Baron Rothschild's assistants, E. Hartert and F. C. R. Jourdain, many of whom gave regular lectures to members.

By 1900, the Society had become strong enough to provide the information published in the natural history section of the "Victoria County History of Hertfordshire". By then, entomology and other invertebrate studies had also become strong, especially moths and butterflies, under the guidance of A. E. Gibbs, and his predecessor J. H. Durrant. Mollusc studies were encouraged by John Hopkinson, who was also an extremely competent geologist, as well as the Society's Secretary for many years

Despite the effects of two World Wars, its reputation for natural history studies grew in the 20th century, and the results were published in its journal, previously the "Transactions of the Hertfordshire Natural History Society", now "The Hertfordshire Naturalist". National figures such as Sir Edward Salisbury, late Director of Kew, and pioneer of ecology as a subject, was Recorder for Botany, and published some important papers in the journal. Other national figures included Charles Oldham, well-known for mollusc studies and for bird studies, F. W. Edwards, of the Natural History Museum, as Recorder for flies, and R. B. Benson, also of the Natural History Museum, as Recorder for sawflies.

Today the Society has a range of special interest groups, which remain in affiliation, including the Herts Bird Club, Herts Moth Group and Herts Flora Group. The Society has also published a number of books, the latest being "Flora of Hertfordshire' in 2009, while our journal is now published in two parts eech year, 'The Hertfordshire Naturalist' and the "Hertfordshire Bird Report", the main publication on the County's birds.

The Society has always tried to be both an organisation for serious study, and an introduction for beginners, bridging the gap between the "expert" and the amateur. It has held lectures, field meetings, discussion groups, seminars and a range of social activities for much of its history, and continues to do so. It has sought to link closely with the many other smaller societies which have sprung up and sometimes disappeared again across the County, encouraging beginners to take a deeper interest. It also was the moving force behind the formation of the Herts & Middx Wildlife Trust in 1963, and continues to have close ties with it.