Somersby is a semi-rural locality of the Central Coast region of New South Wales, Australia, to the northwest of Gosford along the Pacific Highway.

It is part of the Central Coast Council local government area.

The Woolshed Function Centre, Australian Reptile Park, a small industrial area near the Kariong Interchange, two juvenile justice centres, and a primary school are features of Somersby.

Old Sydney Town, now defunct, was a popular tourist destination in Somersby.

Somersby has a number of heritage-listed sites, including: St Francis of Assisi Catholic Church