Interstate 95 (I-95) is a major north–south Interstate Highway that runs along the East Coast of the United States from Miami, Florida, north to the Canada–United States border at Houlton, Maine. In the state of Pennsylvania, it runs from the Delaware state line near Marcus Hook in Delaware County in the southeastern part of the state northeast to the Delaware River–Turnpike Toll Bridge at the New Jersey state line near Bristol in Bucks County, closely paralleling the New Jersey state line for its entire length through Pennsylvania.

From the Delaware state line north to exit 40, the route is officially named the Vietnam Veterans Memorial Highway, but is colloquially known as the Delaware Expressway. North of exit 40, I-95 follows the easternmost portion of the Pennsylvania Turnpike; this portion of road is not signed as part of the turnpike. I-95 parallels its namesake Delaware River for its entire route through the city of Philadelphia and its suburbs. It is a major route through the city and the Philadelphia metropolitan area, providing access to locally important landmarks such as Subaru Park, Philadelphia International Airport, the South Philadelphia Sports Complex, Penn's Landing, and Franklin Mall.

Plans for a limited-access route along the Delaware River in the Philadelphia area originated in the 1930s when both a parkway and elevated highway were proposed; neither of these was built. The Delaware Expressway was approved in 1945 as a toll road that was to be part of the Pennsylvania Turnpike system until the project was turned over to the Pennsylvania Department of Highways in 1956, with the expressway to be included in the Interstate Highway System as part of I-95. Construction on I-95 began in 1959 and was mostly complete by 1979, with the final portion near the Philadelphia International Airport finished in 1985. The route was originally projected to run through the center of Trenton, New Jersey, but was rerouted to the Scudder Falls Bridge to the north due to limited capacity in Trenton. I-95 remained on this alignment until 2018 when the route was truncated to the Pennsylvania Turnpike, being replaced by an extended I-295 north of there. Upon completion of two new high-speed flyovers connecting I-95 and the Pennsylvania Turnpike in 2018, I-95 was extended to the east into New Jersey toward the New Jersey Turnpike along the former I-276 (Pennsylvania Turnpike).

Route description Delaware County I-95 enters Pennsylvania from Delaware in Lower Chichester Township, Delaware County, a short distance north of the southbound exit and northbound entrance with the northern terminus of I-495. The ramp from southbound I-95 to southbound I-495 splits immediately north of the state line. From the Delaware state line, I-95 heads northeast as the Delaware Expressway (Vietnam Veterans Memorial Highway), a six-lane freeway. The route runs through wooded areas, passing over Pennsylvania Route 491 (PA 491) without an interchange and coming to a northbound welcome center and weigh station. The road enters Upper Chichester Township and reaches a partial cloverleaf interchange with Chichester Avenue near the community of Boothwyn. Past this interchange, the freeway passes near residential areas and comes to the partial cloverleaf interchange at PA 452 to the north of the borough of Marcus Hook. I-95 continues east-northeast through woods and heads to the south of CSX Transportation's Twin Oaks Rail Yard, an automotive unloading facility. The road comes to an interchange with U.S. Route 322 (US 322) and Highland Avenue, with I-95 having a southbound exit and northbound entrance with US 322 and a complete interchange with Highland Avenue. At this point, US 322 becomes concurrent with I-95 and the roadway enters the city of Chester, gaining a fourth northbound lane and passing through urban residential neighborhoods. The freeway crosses into Chester Township and heads near more development in the community of Feltonville before US 322 splits from I-95 at a directional T interchange to head southeast on a freeway toward the Commodore Barry Bridge over the Delaware River. US 322 provides access from I-95 to the Chester Waterfront and Subaru Park, the home stadium of the Philadelphia Union of Major League Soccer.

From here, I-95 heads back into the city of Chester and runs between CSX Transportation's Philadelphia Subdivision railroad line to the northwest and urban areas to the southeast, coming to a northbound exit and southbound entrance with Kerlin Street. The freeway narrows to six lanes and continues closely parallel to the railroad tracks, crossing Chester Creek into the borough of Upland and passing to the southeast of the former Crozer-Chester Medical Center on the other side of the railroad. I-95 heads into Chester once again and comes to an interchange with PA 320 and PA 352 as it and the CSX Transportation rail line pass under several city streets. Following this, the freeway curves northeast near urban neighborhoods and crosses Ridley Creek into Ridley Township. Here, the roadway comes to a directional T interchange with the southern terminus of I-476 in the community of Woodlyn, where it also passes over Crum Creek. Past this interchange, I-95 widens to eight lanes and turns to the east away from the CSX Transportation line, passing near residential and commercial development and coming to bridges over US 13 without access and Amtrak's Northeast Corridor railroad line. The road curves east-northeast and enters the southern edge of the borough of Ridley Park, running to the north of Boeing Defense, Space & Security's Vertical Lift helicopter plant. The freeway heads back into Ridley Township as it reaches a diamond interchange with Stewart Avenue that serves Ridley Park. Past this interchange, the highway curves southeast before coming to a bridge over Darby Creek, at which point it enters Tinicum Township. I-95 turns to the east-northeast and passes between the creek to the north and commercial development to the south. The freeway comes to a cloverleaf interchange with PA 420 north of the community of Essington, where the right-most lanes in each direction serve as collector–distributor roads for the interchange. Past this interchange, the eight-lane freeway continues between marshland in the John Heinz National Wildlife Refuge at Tinicum to the north and developed areas to the south. I-95 heads north of an office park before it reaches a northbound ramp that connects to eastbound PA 291. Past this, the freeway comes to a bridge over Conrail Shared Assets Operations' (CSAO) Chester Secondary railroad line and PA 291 (Bartram Avenue).

Philadelphia County

I-95 crosses into the city of Philadelphia in Philadelphia County, at which point it heads to the northwest of the Philadelphia International Airport. The freeway passes under a ramp to the airport's departures terminal and SEPTA's Airport Line as it comes to the northbound exit for the Philadelphia International Airport terminals and a southbound entrance from PA 291 (Bartram Avenue). The road crosses under a ramp to the airport's arrivals terminal and turns to the northeast, reaching a southbound entrance from the airport terminals. The freeway passes under the northbound ramp to the airport terminals and reaches a northbound exit to PA 291 and a southbound entrance from PA 291 as it crosses under the ramp from the airport terminals to southbound I-95. At this point, I-95 gains collector–distributor roads on each side, carrying a 3–3–3–3 lane configuration. The road comes to a southbound exit to the Philadelphia International Airport terminals and PA 291 (Bartram Avenue) and a northbound entrance from the airport terminals. The freeway passes over PA 291 (Island Avenue), where a ramp connects from northbound I-95 to PA 291 and from PA 291 to southbound I-95. I-95 turns east and the collector–distributor roads end, with the roadway becoming eight lanes wide. The road comes to a bridge over PA 291 (Penrose Avenue), where there is a ramp from southbound PA 291 to southbound I-95 and a southbound exit and northbound entrance serving Bartram and Essington avenues. From here, the freeway turns southeast and heads through industrial areas, coming to a southbound exit and northbound entrance with Enterprise and Island avenues, where it also passes over CSAO's 60th Street Industrial Track line. The road narrows to six lanes and curves to the northeast, crossing the Schuylkill River on the Girard Point Bridge, a double-decker cantilever truss bridge.

Past the Schuylkill River, I-95 continues east into South Philadelphia as an elevated freeway through industrial areas to the north of The Navy Yard, a mixed-use development that is located at the former Philadelphia Naval Shipyard. The road passes over CSX Transportation's Harrisburg Subdivision railroad line and heads between Franklin Delano Roosevelt Park to the north and the parallel railroad tracks and The Navy Yard to the south, coming to an interchange with the southern terminus of PA 611 at Broad Street. Past this interchange, the freeway runs between the South Philadelphia Sports Complex to the north and CSX Transportation's Greenwich Yard to the south. I-95 continues east past warehouses to the north and the railroad yard to the south before making a turn to the north, running to the west of CSAO's Swanson Street Industrial Track line and the Port of Philadelphia. The road comes to an interchange connecting to eastbound I-76 (Schuylkill Expressway), which leads to the Walt Whitman Bridge over the Delaware River, and Packer Avenue. The freeway passes under the Walt Whitman Bridge carrying I-76 at this interchange. Past this interchange, I-95 widens to eight lanes and becomes an elevated roadway, running between urban residential areas to the west and commercial areas to the east. Farther north, the freeway comes to an interchange connecting to Christopher Columbus Boulevard and Washington Avenue east of the Queen Village and Society Hill neighborhoods, where it briefly narrows to seven lanes, with three northbound lanes and four southbound lanes, and returns to ground level. Following this, I-95 becomes eight lanes again and passes through the eastern part of Center City. The freeway heads between the Old City neighborhood to the west and Penn's Landing along the Delaware River to the east, where it lowers to a depressed level and passes under two freeway lids. Along this stretch, the road crosses under several city streets including Walnut, Chestnut, and Market streets. I-95 passes under the Benjamin Franklin Bridge, which carries I-676/US 30 and the PATCO Speedline over the Delaware River, before it comes to an interchange connecting to I-676/US 30 (Vine Street Expressway) along with Callowhill Street.