Brookline (/ˈbrʊklaɪn/ ⓘ) is a town in Norfolk County, Massachusetts, United States, and part of the Boston metropolitan area.

An exclave of Norfolk County, Brookline borders six of Boston's neighborhoods: Brighton, Allston, Fenway–Kenmore, Mission Hill, Jamaica Plain, and West Roxbury.

The later annexations of Brighton and West Roxbury, both in 1874, and that of Hyde Park in 1912, eventually made Brookline into an exclave of Norfolk County.

The town has a history of racial discrimination in zoning, which has led to a disproportionately wealthy population and a very low percentage of Black residents, at only 2.5%.

Today, these are Massachusetts Route 9 (locally Boylston St., which cuts the town in two) and the various branches of the MBTA's Green Line.

[2] Once part of Algonquian territory, Brookline was first settled by European colonists in the early 17th century.

The area was an outlying part of the colonial settlement of Boston and known as the hamlet of Muddy River.

In 1843, a racially restrictive covenant in Brookline forbade resale of property to "any negro or native of Ireland.

"[4][5][6] The Town of Brighton was merged with Boston in 1874, and the Boston-Brookline border was redrawn to connect the new Back Bay neighborhood with Allston-Brighton.

This merger created a narrow strip of land along the Charles River belonging to Boston, cutting Brookline off from the shoreline.

It also put certain lands north of the Muddy River on the Boston side, including what are now Kenmore Square and Packard's Corner.

In the 1841 edition of the Theory and Practice of Landscape Gardening, Andrew Jackson Downing described the area this way: The whole of this neighborhood of Brookline is a kind of landscape garden, and there is nothing in America of the sort, so inexpressibly charming as the lanes which lead from one cottage, or villa, to another.

No animals are allowed to run at large, and the open gates, with tempting vistas and glimpses under the pendent boughs, give it quite an Arcadian air of rural freedom and enjoyment.

The Boston and Worcester Railroad was constructed in the early 1830s, and passed through Brookline near the Charles River.

The Highland branch of the Boston and Albany Railroad was built from Kenmore Square to Brookline Village in 1847, and was extended into Newton in 1852.

Streetcar tracks were laid above ground on Beacon Street in 1888, from Coolidge Corner to Massachusetts Avenue in Boston, via Kenmore Square.

Brookline has a history of racial covenants that blocked people of color and some ethnic minorities to own housing there.

John Hull in his youth lived in Muddy River Hamlet, in a little house which stood near the Sears Memorial Church.

The northern part of Brookline, roughly north of the D-line tracks, is urban in character, as highly walkable and transit rich.

The population density of this northern part of town is nearly 20,000 inhabitants per square mile (8,000/km2), similar to the densest neighborhoods in nearby Cambridge, Somerville, and Chelsea, Massachusetts (the densest cities in New England), and slightly lower than that of central Boston's residential districts (Back Bay, South End, Fenway, etc.).

[45] In 2019, Brookline banned the distribution of carry-out plastic bags at grocery stores and other businesses.

[46] In March 2023, the Massachusetts Supreme Judicial Court upheld the bylaw in the case Six Brothers Inc. v. Town of Brookline.

Many students attend Brookline High from surrounding neighborhoods in Boston, such as Mission Hill and Mattapan through the Metropolitan Council for Educational Opportunity system.

As of the 2012–13 school year, the student body was 57.4% White, 18.1% Asian, 6.4% Black, 9.9% Hispanic, and 8.2% multiracial.

The B line runs just to the northwest of Brookline along Commonwealth Avenue, through the Boston University campus and into Allston-Brighton.

It currently operates out of five fire stations located throughout the town, under the command of a deputy chief per shift.