Pennsylvania Plaza (Penn Plaza) is the office, entertainment and hotel complex occupying and near the site of Pennsylvania Station, between 31st and 34th Streets and Seventh and Eighth Avenues in New York.

It includes the current Madison Square Garden and its Theatre, opened in 1968; the current below-ground Pennsylvania Station; and the One Pennsylvania Plaza and Two Pennsylvania Plaza office buildings. (Two Penn is the headquarters of the MSG Network and radio stations WABC and WPLJ.)

Other buildings around the complex use the Pennsylvania Plaza name as an alternate address, such as the 5 Penn Plaza office building on Eighth Avenue, to the northwest; the Pennsylvania Building at 225 West 34th Street (14 Penn Plaza), north of the station; and the Hotel Pennsylvania at 401 Seventh Avenue (15 Penn Plaza), east of the station. The numbering of the Penn Plaza addresses around the area does not follow a consistent pattern.

The Penn Plaza complex remains one of the most controversial in New York City history because it involved the destruction, beginning in 1963, of the original McKim, Mead and White-designed Penn Station (1910), a revered piece of New York architecture. Its replacements were what architects and civic purists regard as mediocre office and entertainment structures.
The demolition of the first Penn Station led to the city's landmarks preservation movement and helped save another landmark of railway architecture, Grand Central Terminal.

What also earned the Penn Plaza critics' ire was the relatively secretive way the decision to raze the old Penn Station came about, even though it was well known that the station's owner, the Pennsylvania Railroad, was losing significant amounts of money and viewed the sale of the Penn Station air rights as a financial boost. (The railroad eventually failed anyway, after its disastrous merger with the New York Central).

Still, with the sports arena and railroad station at its hub and 34th Street retailers (including Macy's) nearing the complex, Pennsylvania Plaza remains one of the busier transportation, business and retailing neighborhoods in Manhattan.