550 Park Avenue, Beaux-Arts apartment building in Upper East Side Historic District, Manhattan, US.

550 Park Avenue is a 17-floor luxury apartment building on Park Avenue on Manhattan's Upper East Side, designed by J.E.R. Carpenter and completed on December 11, 1917. It holds only 32 apartments and stands next to the Browning School.

The building was completed in 1917 when architect J.E.R. Carpenter designed it during a time when wealthy New Yorkers were shifting from townhouses to apartments. This period marked a major change in how the city's upper class chose to live.

J.E.R. Carpenter and his wife were among the first residents of 550 Park Avenue, and the building later housed figures such as financier August Belmont Jr., soprano Hulda Lashanska and fashion editor Diana Vreeland. It was converted to a cooperative in 1952 with only 32 apartments, a small resident group for a 17-floor building.

550 Park Avenue stands on the west side of Park Avenue between East 61st and East 62nd Streets, beside the Browning School. The 17-floor building has only 32 apartments, so the lobby and entrance are private to residents and not open to visitors. The nearest subway stations are several blocks away, and Central Park lies a few blocks west along East 62nd Street.

The building retains original marble entrance galleries and separate service doors, reflecting the social divisions built into New York residential design from that era. These dual access systems reveal how class boundaries were considered when designing luxury apartments.