Stamford station, officially known as the Stewart B. McKinney Transportation Center or the Stamford Transportation Center, is a major railroad station in the city of Stamford, Connecticut, serving passengers traveling on Metro-North Railroad's New Haven Line, and Amtrak's Northeast Corridor. In addition, it is also a major bus terminal for Greyhound, Peter Pan, and CTtransit buses. In 2018, the station averaged over 15,000 Metro-North boardings on weekdays, making it the busiest station on the system aside from Grand Central Terminal. Its official name honors politician Stewart McKinney.

The split for the New Canaan Branch is just northeast of the station. Downtown Stamford is directly north of the station; the entrance to the station on the north side is marked by the Stamford Cone, a work of public sculpture situated at the top of Gateway Commons, while the South End is located directly south.

The station has a 9-car-long side platform on the south side, a 10-car-long platform on the north side and two high-level 12-car-long island platforms. The main station concourse straddles the tracks of the Northeast Corridor, and contains the ticket booth, a passenger waiting area, and shops. Below the platform level is an MTA police station, other shops, a Greyhound/Peter Pan office and CT Transit Customer Information Center. Stairs and escalators lead to the platform level. On the south side of the station, across an access street, is a large parking garage connected to the concourse by one pedestrian bridge and directly connected to the east end of the platforms by a second bridge (both bridges connect to Level 4 of the garage).

A bus station is located just to the north of the train station, underneath a large bridge carrying Interstate 95. Taxis pick up passengers at a stand on the south side of the station. A car rental agency is located southwest of the station building.

Stamford receives very frequent rail service on the New Haven Line. During peak hours, trains at Stamford come in intervals as little as three or seven minutes apart. Reverse commute trains during rush hours also operate relatively frequently, at intervals of ten to twenty minutes. Off-peak trains in both directions arrive at Stamford every thirty to forty minutes, but usually within a half-hour of each other. Stamford is the busiest Metro-North Railroad station other than Grand Central Terminal, averaging 15,000 boardings on weekdays in 2018.

The station divides the New Haven Line into an outer zone and an inner zone. Outer zone trains usually run local from New Haven to Stamford, then run express to Grand Central, normally stopping only at Harlem-125th Street. Inner zone trains usually originate here and run local all the way to Grand Central. Passengers transferring between zones can make cross-platform interchanges in Stamford.

In the 2000s, Stamford and Greenwich received increasing numbers of reverse commuters who work in Stamford but live in New York City. Reverse commuting doubled from 1997 to 2007, with 1,900 daily reverse commuters by 2007. Metro-North added trains and express service to serve these commuters. As financial companies moved to Stamford from Manhattan, some employees became reverse commuters. Larger companies farther away than a few minutes walk from the station routinely provided shuttle service for their workers.

As of 2014, Stamford has been a central stop for a special "Yankee Clipper" Train. The direct train runs to and from all weeknight and weekend games to Yankees–East 153rd Street to serve New York Yankees baseball games and New York City FC soccer matches at Yankee Stadium. The trains are timed to arrive between 45 minutes and 2 hours prior to the start of the game, and depart between 20 and 45 minutes after they end.

Due to ridership growth, ConnDOT announced on March 19, 2007 that it would extend more Shore Line East trains to Stamford during peak hours. To coincide with the extension of this service, Metro-North added another five trains on the New Haven Line to cope with the increases in passenger demand at Stamford. Shore Line East service to Stamford was suspended indefinitely on March 16, 2020, due to the coronavirus pandemic. Service resumed on October 7, 2024.

Amtrak also operates three routes which stop at Stamford: the Acela, the only high-speed rail service in the United States, the Northeast Regional, providing local service along the Northeast Corridor, on which Stamford is a vital station, and the Vermonter, the only train from Connecticut that goes to Vermont. Stamford is now the second-busiest Amtrak station in Connecticut, after New Haven's Union Station.

Regular daily train service began in Stamford on January 1, 1849. In 1867, a depot was built one block east of the present location. The railroad at that time consisted of two tracks and passed through town on ground level (crossing the streets at grade). In the mid-1890s, two more tracks were added to the line and most crossings were elevated and bridged; the 1867 depot was razed and replaced.

In 1980, the Federal Railroad Administration (FRA) awarded $50 million for a new station and parking garage in Stamford. The cost was paid 70% by the FRA, 20% by the state, and 10% by the city. Construction began in 1983. Garage construction was soon halted due to cracks in support beams caused by a contractor omitting components. Additional of a support column failed to solve the issue; the FRA took over the project. The garage and station opened in 1987.

Architecture critic Paul Goldberger, writing for The New York Times in 1987, criticized the station for "a harshness almost unequaled in contemporary architecture" as well as for cost overruns and many functional failings, including the lack of shelter for the track platforms. The route from the cross-tracks waiting room to the platform was so long and indirect that passengers who waited indoors until a train's arrival was announced could not get to the platform in time to board it. Despite these issues, Stamford became the line's busiest station aside from Grand Central by 1989.

A complete renovation of the station in the early 2000s, provided for in the original design of the overhead structure, addressed the problems. The two platforms were made island platforms, capable of serving four tracks. Added features included platform canopies, stairs and escalators directly from the waiting room for the tracks, and a new platform crossover, connecting to a 1,200-space addition to the parking garage.

In 2006, the state indicated plans to replace the 1987-built garage. That plan was cancelled in 2008; by 2012, the state planned to pursue privately-funded transit-oriented development on the garage parcel, with replacement parking possibly located up to a quarter-mile away. Temporary repairs to the deteriorating original garage were made in 2015; even so, only 200 of the 727 spaces were usable by 2019.

Construction of a new 928-space, $82 million parking garage northwest of the station began in October 2021. Located over State Street includes a 320-foot (98 m)-long footbridge connecting to the main waiting room plus a ramp to the southbound (Track 5) side platform. After delay, the new garage opened on February 26, 2024. This allowed demolition of the 1980s-built garage and footbridge (at a cost of $9 million) to begin. Demolition of the footbridge took place from March 11 to late April 2024, followed by demolition of the garage. Demolition is expected to be complete by late 2024.

• Stamford, CT – Amtrak
• Stamford, CT – Station history at Great American Stations (Amtrak)

• Metro-North station page for Stamford Transportation Center
• List of upcoming Metro-North train departure times and track assignments from MTA
• Washington Boulevard entrance from Google Maps Street View
• Entrance south of tracks from Google Maps Street View
• Station Building on State Street from Google Maps Street View
• Stamford Amtrak-Metro North-Shore Line East Station (USA Rail Guide - Train Web)
• Historic American Engineering Record (HAER) No. CT-9, "New York, New Haven & Hartford Railroad, Stamford Station, 44 Station Place, Stamford, Fairfield County, CT", 15 photos, 25 data pages, 1 photo caption page