b9
60th Street Line Avenue M Line
A 2017 XN40 (777) on the Bay Ridge-bound B9 at Flatbush/Schenectady Avenues
Overview
System	MTA Regional Bus Operations
Operator	New York City Transit Authority
Garage	Jackie Gleason Depot Ulmer Park Depot (school trippers)
Vehicle	New Flyer C40LF New Flyer Xcelsior XN40 New Flyer Xcelsior XD40 (school tripper only)
Began service	October 28, 1931
Route
Locale	Brooklyn, New York, U.S.
Communities served	Bay Ridge, Sunset Park, Borough Park, Bensonhurst, Mapleton, Midwood, East Midwood, Flatlands, Marine Park, Old Mill Basin [1], Mill Basin
Start	Bay Ridge – Shore Road and 71st Street
Via	Shore Road, Narrows Avenue/71st Street (westbound only), Bay Ridge Avenue, Fourth Avenue, 60th Street, Avenue N, Ocean Parkway, Avenue M, Ocean Avenue, Avenue L, Flatbush Avenue
End	Marine Park/Mill Basin - Kings Plaza at Flatbush Avenue and Avenue U Flatlands - Flatbush Avenue and Avenue L (early morning/late evening terminus)
Length	8.0 miles (12.9 km)
Service
Operates	4:45 AM - 1:45 AM
Annual patronage	2,934,311 (2023)[2]
Transfers	Yes
Timetable	B9
Route map ← B8  {{{system_nav}}}  B11 →

The B9 is a bus route in the New York City borough of Brooklyn, which serves the corridor of 60th Street, plus some of Avenue M and Avenue L. Originally operated by the Brooklyn-Manhattan Transit Corporation, it is now operated by MTA Regional Bus Operations under the New York City Transit brand.

The B9 route begins at Shore Road and 71st Street in Bay Ridge. It turns right onto Bay Ridge Avenue, and then left onto Fourth Avenue. Next, it turns right onto its main corridor, 60th Street. It continues until the end, running straight onto Avenue N. Then it starts running in a squiggle pattern, heading left onto Ocean Parkway, right onto Avenue M, left onto Ocean Avenue, and left onto Avenue L. It continues on Avenue L until Flatbush Avenue, where it makes a right, then heads straight to Kings Plaza, terminating at the bus loop. The westbound route heads back to its Bay Ridge terminal via Narrows Avenue and 71st Street. Early morning and late evening service terminates at Flatbush Avenue and Avenue L in Flatlands.^[3][4]

The B9 is based out of Jackie Gleason Depot, which operates buses that run on compressed natural gas. On school days, Ulmer Park Depot provides trippers from 60th Street and 20th Avenue to Xaverian High School, where the Bay Ridge terminal is, and from the school to Flatbush Avenue and Avenue L, using regular diesel buses.

The B9 began service on October 28, 1931 under the operation of Brooklyn-Manhattan Transit, which was sold to the City on June 1, 1940. It originally used Third Avenue between Bay Ridge Avenue and 60th Street.

On June 14, 1980, the B9 began summer weekend service to Jacob Riis Park in Rockaway, Queens, which lasted throughout the 1980s. Service would run every 30 minutes between 8 a.m. and 7 p.m., and when the service was announced four days earlier, it was expected that service would be increased as ridership increased. The extensions in service were made possible via federal funding from the Gateway National Recreational Area.^[5][6][7] In September 2006, the B9 was rerouted from Third Avenue to Fourth Avenue, in order to improve connections to and from the subway.^[8]

On December 1, 2022, the MTA released a draft redesign of the Brooklyn bus network. As part of the redesign, the current B9 route would remain, but closely-spaced stops would be eliminated.^[9]