Eastern Parkway is a major east–west boulevard in the New York City borough of Brooklyn. Designed by Frederick Law Olmsted and Calvert Vaux, it was built between 1870 and 1874 and has been credited as the world's first parkway. At the time of its construction, Eastern Parkway extended to the eastern edge of the then-independent city of Brooklyn.

The road begins at Grand Army Plaza (the main entrance to Prospect Park) and runs 3.8 miles (6.1 km) east to Bushwick Avenue. The initial portion of Eastern Parkway, west of Ralph Avenue, consists of a main road and two service roads separated by landscaped medians, which include bike paths and walkways. The section west of Ralph Avenue is a New York City scenic landmark and on the National Register of Historic Places. The part east of Ralph Avenue is narrower and is officially known as the Eastern Parkway Extension.

Olmsted and Vaux designed Eastern Parkway, along with Ocean Parkway, in the 1860s to connect Prospect Park with neighborhoods further afield. Eastern Parkway was built with the expectation that it would be the centerpiece of a neighborhood with "first-class" housing. Ultimately, the resulting development encompassed a variety of building styles including single-family homes, mansions, and apartment buildings. Eastern Parkway has been modified several times over the years. The extension east of Ralph Avenue was built in the late 1890s, and the original parkway's service roads were widened in the 1900s. The neighborhoods around the parkway developed into Doctor's Row in the late 19th century, and further development occurred with the opening of the New York City Subway’s IRT Eastern Parkway Line in 1920. Following a period of deterioration, the section between Washington and Ralph avenues was rebuilt between 1987 and 1993, and the section west of Washington Avenue was rebuilt in the 2000s. By the 21st century, Eastern Parkway had some of Brooklyn's most dangerous intersections.

Eastern Parkway extends 3.8 miles (6.1 km) across Brooklyn from west to east. Its western terminus is at Grand Army Plaza (originally Prospect Park Plaza), the main entrance to Prospect Park, where it intersects with Prospect Park West, Flatbush Avenue, and Vanderbilt Avenue. From Grand Army Plaza to Washington Avenue. the thoroughfare consists of a broad, bidirectional avenue of six lanes, separated by a median from a narrow parallel service road on the north side. It passes Brooklyn Central Library, Brooklyn Museum, Mount Prospect Park, and Brooklyn Botanic Garden in this area; all of these are located on the south side of Eastern Parkway. The section between Washington and Ralph avenues has a second service road on the south side, separated by another median. The parkway makes a slight bend at Bedford Avenue, and it continues east to Ralph Avenue.

East of Ralph Avenue, the parkway is reduced to six lanes, heading in a northeasterly direction toward Bushwick Avenue. Here, Eastern Parkway officially becomes the Eastern Parkway Extension and curves to intersect with Howard Avenue, Atlantic Avenue, Fulton Street, and Broadway. In this area, Eastern Parkway runs diagonally to the rest of the street grid, creating several oblique intersections. At Bushwick Avenue, the Extension becomes Vanderveer Street, a dead-end street. The extension connects to the Jackie Robinson Parkway, three blocks southeast, via Bushwick Avenue.

East of Ralph Avenue, the address numbers on Eastern Parkway continue down Pitkin Avenue toward Aqueduct Racetrack. Pitkin Avenue was created by the late 1890s when the Eastern Parkway Extension was constructed. Eastern Park, the home of the Brooklyn Dodgers before Ebbets Field, was located at Eastern Parkway and Vesta Avenue (now Pitkin Avenue at Van Sinderen Avenue, respectively).

In Crown Heights, Eastern Parkway divides the black community to the north and the Jewish community to the south. There have historically been tensions between the two demographic groups, especially after the 1991 Crown Heights riot, which occurred after one of the cars in Chabad-Lubavitch Rebbe Menachem Mendel Schneerson's motorcade struck two Guyanese children. Eastern Parkway also divides the two community boards that serve Crown Heights: Brooklyn Community Board 8 to the north and Brooklyn Community Board 9 to the south. One news reporter wrote in the 1990s that, although Eastern Parkway's apartment buildings and rowhouses were typical of a mid-20th-century American middle-class neighborhood, its West Indian and Jewish populations "created a world that sometimes resembles two vastly different countries".

The New York City Landmarks Preservation Commission and New York City Department of Parks and Recreation credit Eastern Parkway as the world's first parkway, built explicitly for personal and recreational traffic while restricting commercial traffic. Frederick Law Olmsted, the parkway's co-designer, described a parkway as "a shaded green ribbon" which might "be absolutely formal or strikingly picturesque, according to circumstances."