Peconic Bay scallops are a population of northern bay scallops (Argopecten irradians subsp. irradians) found in the Peconic Bays of eastern Long Island. They are known as a regional culinary specialty and an important part of aquaculture in New York. The history of harvesting Peconic Bay scallops has been dated to the Late Woodland period, 1,000 to 1,500 years ago.

Bay scallops inhabit shallow bays with a range from Cape Cod to parts of Florida and Texas. Peconic Bay scallops are a northern subspecies of bay scallops that are found in the Peconic Estuary, between the northern and southern forks of Long Island. In the estuary, scallops spawn typically in early June, followed by a one- to two-week larval stage where the larvae are free-swimming, and eventually move out of the water column and into beds of eelgrass. The time of spawning varies by place as well as year, but typically occurs between late May and early June, with some years occurring in late July; it is also possible for second and third spawns to occur in late August or mid-September.

Peconic Bay scallops, like all bay scallops, are functional hermaphrodites that release both sperm and eggs alternately in the course of a single spawning event; spawning in the Peconic Bays usually begins between late May and mid-July, but spawn seasons have been recorded starting as late as September and October. Most scallops spawn during their first year of life and have a life expectancy between 18 and 22 months. Historically this has been advantageous for the Peconic Bay fishing industry as the adult scallops were fished without a presumed need for catch restrictions, as the majority of scallops would die in a short while if they were not caught. This life cycle makes scallop populations prone to large fluctuations in a short period of time, and therefore, the scallop industry very precarious.

Bay scallops, like hard clams and other shellfish species, are critical for filtering water and as a link in the estuary's food web.

Bay scallops are able to move by closing their two valves and shooting jets of water to propel themselves, unlike most other species of shellfish.

Archeological evidence of Native American communities, including the Shinnecock Indian Nation, harvesting scallops in the Peconic Bays is robust. Large numbers of scallop shells have been discovered on locations around eastern Long Island, including Robins Island, Shelter Island, and Orient.

Beginning in the 1870s, the northern bay scallop fishery was an engine of economic growth in communities on and around the Peconic Bays, as well as other coastal communities along the eastern seaboard of the United States. For the following century, Peconic Bay scallops were an important part of the economy, particularly in the winter when other business activity decreased; Peconic Bay scallops are considered the "jewel" of eastern Long Island’s recreational and commercial fishery. In February 1900, thousands of bushels of scallops washed up onto the shores of Peconic Bay.

Records of scallop population collapse date to as early as the 1930s, when eelgrass wasting disease destroyed the scallop's preferred habitat and the population subsequently plummeted. Beginning in 1985 and continuing into 1988, a series of harmful blooms of Aureococcus anophagefferens, also known as a brown tide, occurred in the waters around Long Island and decimated scallop populations. Although restoration efforts began in 1986 and populations began to increase again, another severe brown tide occurred in 1995; the total commercial harvest in New York of 1996 was 53 lbs, compared to a pre-brown tide annual average of 300,000 lbs.