Berkeley Township is a township in Ocean County, in the U.S. state of New Jersey, extending from the Jersey Shore westward into the New Jersey Pine Barrens. As of the 2020 United States census, the township's population was 43,754, the highest ever in any decennial count and an increase of 2,499 (+6.1%) from the 2010 census count of 41,255, which in turn reflected an increase of 1,264 (+3.2%) from the 39,991 counted in the 2000 census.

Berkeley Township was incorporated as a township by an act of the New Jersey Legislature on March 31, 1875, from portions of Dover Township (now Toms River Township). Sections of the township were taken to form Seaside Park (March 3, 1898), Seaside Heights (February 6, 1913), Beachwood (March 22, 1917), Ocean Gate (February 28, 1918) Pine Beach (February 26, 1925), South Toms River (March 28, 1927), and Island Beach (June 23, 1933, reabsorbed into Berkeley Township in 1965). The township was named for John Berkeley, 1st Baron Berkeley of Stratton, one of the founders of the Province of New Jersey.

Army officer Lt. Edward Farrow began buying up woodland in the 1880s with the idea of building a retirement community for former Army and Navy officers. Farrow built a railroad station, shops and even a resort hotel called The Pines with the idea of attracting people. But only 11 people ever built houses in what Farrow called "Barnegat Park," and eventually he went bankrupt.

In the 1920s, Benjamin W. Sangor purchased the area, intending to create a resort town catering to wealthy urban vacationers. Between 1928 and 1929, about 8,000 lots were sold in Pinewald, a "new-type, residential, recreational city-of-the sea-and-pines." It was to contain a golf course, recreation facilities, and estate homes.

The developers immediately began construction of the Pinewald pavilion and pier at the end of Butler Avenue. The Royal Pines Hotel, a $1.175 million investment facing Crystal Lake, was built on the site of an earlier hotel dating back to the days of Barnegat Park. It was the focal point of the new community. The hotel was also used as an asylum, then later a nursing home now known as the Crystal Lake Nursing & Rehabilitation Center.

The hotel was constructed by Russian architect W. Oltar-Jevsky in the early 1920s. Al Capone may have frequented its halls, perhaps even venturing beneath the lake in tunnels especially designed for smuggling alcohol during Prohibition. One newspaper article interviewed an unidentified man who claimed that "in the early 1930s the then Royal Pines Hotel was frequented by society's elite who, for $1.90 a drink, consumed prohibition liquor under the watchful eye of men who had guns strapped under their coats." In 1929, during the Great Depression, this resort community also went bankrupt.

In September 2014 residents of the South Seaside Park neighborhood of Berkeley Township submitted a petition to move from the township and become a part of the borough of Seaside Park, arguing that the neighborhood was 16 miles (26 km) away from the township's municipal offices and that there were minimal social connections with the rest of Berkeley Township. In 2025, the New Jersey Supreme Court approved the petition and agreed that South Seaside Park may leave the township and join Seaside Park borough.

According to the United States Census Bureau, the township had a total area of 54.25 square miles (140.51 km²), including 42.72 square miles (110.64 km²) of land and 11.53 square miles (29.87 km²) of water (21.26%).