The Providence/Stoughton Line is an MBTA Commuter Rail service in Massachusetts and Rhode Island, primarily serving the southwestern suburbs of Boston.

The line is the busiest on the MBTA Commuter Rail system, with 17,648 daily boardings in an October 2022 count.

[3][4] On December 31, 1968, the recently formed Penn Central bought the failing New York, New Haven and Hartford Railroad.

Full subsidies by the MBTA for the Providence and Stoughton lines began on September 28, 1976, before which the Federal government helped.

On March 31, 1977, the Greater Attleboro Taunton Regional Transit Authority and Rhode Island Department of Transportation began to subsidize service beyond the MBTA district, and Stoughton began to pay to keep its station open, that cost later going to the Brockton Area Transit Authority.

On November 3, 1979, the line was closed north of Readville for long-term reconstruction as part of the Southwest Corridor project.

On February 20, 1981, the MBTA stopped serving Rhode Island altogether after that state declined to renew its subsidy.

On June 20, 1990, a new stop opened in South Attleboro and most trains were extended to the station; regular Sunday service returned in 1992.

[8][9][10] The South County Commuter Rail initiative, a 20-mile extension past Providence to T. F. Green Airport and Wickford Junction in Rhode Island was implemented between 2010 and 2012.

The T. F. Green Airport part of the extension opened in December 2010, with Wickford Junction service beginning in April 2012.

[12][13] Additional studies and proposals to expand Providence Line service have occurred; though none have been funded or pursued.

[14] Ultimately, the MBTA would be contracted to operate trains as far as Wickford Junction, with Kingston and Westerly being relegated to only Northeast Regional service.

[17]A major extension of the Stoughton Branch has been proposed as a part of Phase 2 of the South Coast Rail project.

Currently, the line between Stoughton and Dean Street in Taunton is abandoned; however, the route is rail-banked for future service, precluding it from overdevelopment.

Electrified commuter service had not been pursued due to costs associated with traction substation expansion, electric multiple unit procurement, as well as additional catenary installation at several station sidings and layover facilities.

[19][20] By the late 2010s, the MBTA began exploring options to pilot electric trains for Providence service as part of a long-term transition to regional rail.

In 2019, the MBTA had preliminary discussions with Amtrak about leasing Siemens ACS-64 electric locomotives to test on the Providence Line.

[26][27] In July 2024, the MBTA and Keolis moved forward with a proposal to procure and operate BEMUs on the Fairmount Line by 2028; however, Providence service was omitted due to increased fleet requirements.

[46][5] As part of a schedule change on January 23, 2021, Sunday morning Boston–Providence service began operation for the first time since the New Haven era.

[48] As part of that schedule change, all Providence/Stoughton Line trains began stopping at Ruggles station after an additional platform there was completed.

All Acela Express trains and all Northeast Regional routes between Boston and New York City run along this line.

With fast and frequent MBTA and Amtrak service, the Providence-Boston share of the Northeast Corridor is one of the busiest rail lines in the country.