The Martin Luther King Jr. East Busway is a two-lane bus-only highway serving the city of Pittsburgh and many of its eastern neighborhoods and suburbs. It was named after Martin Luther King Jr. in recognition of the eastern portion of the route's serving many predominantly African-American neighborhoods, such as Wilkinsburg and East Liberty. It is owned and maintained by Pittsburgh Regional Transit.

The Institute for Transportation and Development Policy (ITDP), under its BRT Standard, has given the East Busway corridor a Bronze ranking.

Originally occupied by a railroad line, planning for the East Busway began shortly after the Port Authority of Allegheny County purchased the Pittsburgh Railways Company in 1964. The original segment of the busway opened in February 1983, running between Downtown Pittsburgh and Edgewood, a length of 6.8 miles.

In 2003, the busway was extended into Swissvale by 2.3 miles (3.7 km), making its current length 9.1 miles (14.6 km).

In July 2013, the East Busway was discussed in the context of the Mon Fayette Expressway.

Following the naming convention of each busway being designated by a color, bus routes that use the East Busway begin with a "P" for purple. However, the P13 (Mount Royal Flyer) is colored purple and uses a "P" designation, but does not use the busway; instead, it travels via Route 28. The P1 ("East Busway All Stops") is the main route, operating seven days a week and running the full length of the Busway between Swissvale and Downtown Pittsburgh, making all stops, before running a short loop through the central business district. It is the busiest Pittsburgh Regional Transit bus route by ridership.

All busway routes travel to downtown Pittsburgh, making a loop around before returning via the busway. The one exception to this is the P3 (East Busway-Oakland), which starts in Swissvale, but leaves the busway via the Neville Street Ramp, serving the business district of Oakland and terminating at Robinson Street.

Many of Pittsburgh Regional Transit's express and suburban Flyer routes also use the busway, but with stop restrictions, not picking up passengers at some busway stations in the inbound direction or dropping off passengers at some busway stations in the outbound direction. These routes operate primarily during weekday rush hours allowing buses to bypass the heavily congested Parkway East (Interstate 376), making for faster trip times. The East Busway is also used by some Westmoreland Transit routes, which run further into the Pittsburgh suburbs, ending in the cities of Greensburg and Latrobe in Westmoreland County.

As of February 2024, the Pittsburgh Regional Transit bus routes that use the East Busway are as follows:

Route	Route Name	Destination	Roads Traveled	Notes
P1	East Busway All Stops	Swissvale station	East Busway	Daily, all-day service
P3	East Busway-Oakland	5th Av & Robinson St	Neville St/5th Av	Weekdays only
P7	McKeesport Flyer	McKeesport Transportation Center	Edgewood Av/Rankin Bl/Kennywood Bl	Weekday peak hours only, stop restrictions
P10	Allegheny Valley Flyer	Harrison	Route 28/Freeport Rd
P12	Holiday Park Flyer	Holiday Park	Penn Av/Parkway East/Golden Mile Hwy
P16	Penn Hills Flyer	Alpha Ice Complex, Harmar	Leechburg Rd or Universal Rd
P17	Lincoln Park Flyer	Nadine	Lincoln Av/Mt Carmel Rd
P67	Monroeville Flyer	Monroeville Mall	William Penn Hwy
P68	Braddock Hills Flyer	Forbes Hospital	Brinton Rd/Braddock Av/James St	Daily, all-day service, stop restrictions
P69	Trafford Flyer	Viaduct Way, Trafford	Ardmore Bl/Airbrake Av/Broadway Bl	Weekday peak hours only, stop restrictions
P71	Swissvale Flyer	Swissvale station	Savannah Av/Braddock Av/Woodstock Av
P76	Lincoln Highway Flyer	Olympia Park and Ride	Ardmore Bl/Lincoln Hwy/Long Run Rd
P78	Oakmont Flyer	Alpha Ice Complex, Harmar	Laketon Rd/Verona Rd/Allegheny River Bl	Weekdays only, stop restrictions

Station Name	Neighborhood/Borough	Routes	Notes
Penn Station	Downtown	P1   P7   P10   P12   P16   P17   P67   P68   P69   P71   P76   P78	Amtrak: Floridian, Pennsylvanian Greyhound Lines
Herron	Polish Hill	P1   P7   P10   P12   P16   P17   P67   P68   P69   P71   P76   P78
Negley	Shadyside	P1   P3   P7   P10   P12   P16   P17   P67   P68   P69   P71   P76   P78
East Liberty	East Liberty	P1   P3   P7   P10   P12   P16   P17   P67   P68   P69   P71   P76   P78
Homewood	Homewood, Point Breeze North	P1   P3   P7   P12   P16   P67   P68   P69   P71   P76   P78
Wilkinsburg	Wilkinsburg	P1   P3   P7   P12   P16   P67   P68   P69   P71   P76   P78	Park and ride: 748 spaces
Hay Street		P7   P12   P16   P67   P68   P69   P71   P76   P78	Located on spur to Hay Street
Hamnett		P1   P3	Park and ride: 128 spaces
Roslyn	Swissvale	P1   P3
Swissvale		P1   P3	Park and ride: 163 spaces

• West Busway
• South Busway
• Pittsburgh Light Rail

• Port Authority of Allegheny County: East Busway information page
• East Busway Schedule and Map – P1 & P3