North Philadelphia, nicknamed North Philly, is a section of Philadelphia, Pennsylvania. It is immediately north of Center City. Though the full extent of the region is somewhat vague, "North Philadelphia" is regarded as everything north of either Vine Street or Spring Garden Street, between Northwest Philadelphia and Northeast Philadelphia. It is bordered to the north by Olney Ave along Broad Street, Spring Garden Street to the south, 35th Street to the west and Adams Avenue to the east. The Philadelphia Police Department patrols five districts located within North Philadelphia: the 22nd, 25th, 26th, 35th and 39th districts. There are thirteen ZIP Codes for North Philadelphia: 19120, 19121, 19122, 19123, 19125, 19126, 19130, 19132, 19133, 19134, 19137, 19140 and 19141.

The city government views this sprawling chunk of Philadelphia more precisely as three smaller districts, drawn up by the Redevelopment Authority in 1964. These regions are (from north to south) Olney-Oak Lane, Upper North Philadelphia and Lower North Philadelphia. Other sections of North Philadelphia include Brewerytown, Fairhill, Fairmount, Francisville, Franklinville, Glenwood, Hartranft, Koreatown, Northern Liberties, Poplar (roughly bound by Girard Avenue, Broad Street, Spring Garden Street and 5th Street), Sharswood, Strawberry Mansion, and Yorktown.

Prior to its incorporation into the city proper, North Philadelphia was little more than a collection of primarily agricultural townships north of the original City of Philadelphia. In the 18th century, as Philadelphia grew in importance and, consequently, population, then pastoral North Philadelphia became an attractive alternative to the burgeoning city. The mansions of wealthy Philadelphians began to dot the landscape, and by the late 18th and early 19th century, several small town centers had developed to anchor the growing population. However, this suburban landscape was to be interrupted around the middle of the 19th century, as rapid urban expansion led to The Consolidation Act of 1854. This state law annexed all of the townships within Philadelphia County to the City of Philadelphia. With new territory now under the aegis of Philadelphia's city planners, a rising influx of European immigrants led to the end of North as a suburb of Philadelphia. North Philadelphia's decentralized towns were gradually meshed into a sprawling network of the ubiquitous Philadelphia rowhouses. A number of the newly created neighborhoods retained the name of their ancestral towns and townships, for example, Northern Liberties was formerly Northern Liberties Township.

Philadelphia was one of the most important centers of manufacturing in the world between the mid-19th and mid-20th centuries, and North Philadelphia is one of the sections of the city whose landscape was most deeply shaped by the industrial era. Its landscape still strongly reflects this heritage.

As the industrial age peaked in America, North Philadelphia became a working man's town. Upper North Philadelphia, Olney, Brewerytown, became major hubs of production. Large factories and industrial complexes were erected, covering vast swaths of city land. Thousands of row homes were constructed to house the burgeoning worker population. This expansion was also the impetus for breaking ground on the Broad Street Line subway, designed specifically to carry a passenger from the northern hub of Olney to Philadelphia City Hall in under 20 minutes. Major freight and passenger rail lines were built to intersect at the newly constructed North Broad Street Station and transmit cargo from the bustling factories. The completion of the BSL these major railways made the region a thriving hub of transportation. For a time, North Philadelphia station became the second most heavily trafficked rail station in the city, and the Olney Ave station the most used subway stop.

Along with a number of Philadelphia's major manufacturing concerns came the nearby estates of the wealthy industrialists who had founded them. Lower North Philadelphia in particular housed a number of the nouveau riche: ambitious first or second generation immigrants or those that had made their fortunes starting manufacturing firms. Many were German Jews who had settled in the area, later founding companies and building synagogues. For a time, an age of opulence and grand architecture returned to North Philadelphia, centered on what is now zoned as the Historic North Broad Street Mansion and Speculative Housing Districts. Gentlemen's clubs, upscale restaurants and shopping districts grew in this southern tier for a brief moment in history, peaking in the late 1920s. Upper-class foremen and executives lived farther north along Broad Street, in what is now the West Diamond Street Townhouse Historic District. Thriving commercial districts sprung up along the great northern avenues: Columbia (renamed Cecil B. Moore Avenue), Susquehanna, Dauphin, Erie, Lehigh and Olney, to name a few. However, just as this wealth was so suddenly gained, it would just as suddenly be lost. The new money culture proved to be an unstable foundation for a lasting community, and like so many constructs of the Gilded Age, this core of wealth was doomed to rot.

Over the next few decades The Great Depression, outsourcing and white flight took their toll on North Philadelphia in a fashion similar to other major US cities of the mid to late 20th century, if not in a more pronounced fashion. While residential corridors like Hope Street and Delhi Street had long housed primarily African-American residents, white residents moved out of the city as waves of poorer black residents moved in. During the 40s and 50s, much of the area was racially integrated, although smaller streets were usually completely black or white. Whites began to move out slowly at first in the late 1940s as these residents became more affluent and Northeast Philadelphia began to develop new housing with lawns and conveniences such as modern plumbing. In most cases African Americans moved into the vacant houses and as this began to increase, true white flight began. Increasingly, people moved out of North Philadelphia not solely to move into newer homes, but to avoid facing decreasing property values and increased criminality. For a time, Lower North Philadelphia became a great center of black culture and music, most notably jazz. A number of commercial corridors were maintained for decades, and multiple musicians came to North Philadelphia, like John Coltrane and Stan Getz. By 1964, North Philadelphia was the city's center of African American culture, home to 400,000 of the city's 600,000 black residents.

As the century marched past middle age, other problems symptomatic of all US cities of the time came about. Some of the neighborhoods in North Philadelphia sprung up around one monolithic factory, which was the center of the community's income. Each factory that closed down devastated its host neighborhood. In this way, the wave of national industrial collapse caused the rapid break up of numerous "factory neighborhoods" in the predominantly working class North Philadelphia.