*The cathedral is built of brick, not marble because brick is stronger. However, it was then covered with marble, quarried in New York and Massachusetts.
- It can accommodate 2,200 people.
- The site of the church takes up a whole city block, bounded by East 51st Street to the north, Madison Avenue to the east, East 50th Street to the south, and Fifth Avenue to the west.
- The spires rise 330 feet (100 m) from street level.
- The windows were made by artists in Chartres, France, Birmingham, England and Boston, Massachusetts. The great rose window is one of Charles Connick's major works.
- The Saint Michael and Saint Louis altar was designed by Tiffany & Co. The Saint Elizabeth altar was designed by Paolo Medici of Rome, Italy.
- The Saint John Baptist de la Salle altar remains one of the few original side-chapel altars commemorating the patron saint of catechists and teachers. The adjoining stained-glass window depicts the Papal bull (a type of letters patent) of approbation granted by the Vatican to the Institute of the Brothers of the Christian Schools who, since 1848, have conducted numerous parish grade and high schools throughout the Archdiocese of New York, as well as Manhattan College, Riverdale (in The Bronx borough of New York City) and Lincoln Hall.
- The cathedral's Stations of the Cross won a prize for artistry at the 1893 World's Columbian Exposition in Chicago, Illinois.
- The Pietà is three times larger than Michelangelo's Pietà. It was sculpted by Araldo Perugi, who immigrated from Carrara, Italy.
- A bust of Pope John Paul II is located in the rear of the cathedral, commemorating his visit to the city in 1979.
- Archbishop Francis Spellman, later cardinal, undertook a major renovation of the cathedral's main altar area in the late 1930s and early 1940s. The bronze baldachin in the sanctuary is part of this work, and the former high altar and reredos that stood there were removed and replaced. The original high altar of Saint Patrick's is now in the University Church of Fordham University in The Bronx (Spellman's alma mater). Coincidentally, that church, built in the 1830s, is also home to stained-glass windows donated by French King Louis-Philippe I for Saint Patrick's Old Cathedral downtown when it was originally being built. The windows were installed in the University Church when it was discovered that they did not fit in the Old Saint Patrick's. Clendenin J. Ryan donated the rose window. He was the grandson of Thomas Fortune Ryan and Ida Barry Ryan who built the Church of St. Jean Baptiste at East 76th Street and Lexington Avenue.
- In the 1980s, Cardinal John Joseph O'Connor undertook further renovation work, most notably the construction of a new stone altar in the middle of the sanctuary, closer and more visible to the congregation. It was built from sections of one of the side altars that were removed to reposition the baptismal font in the north transept.
- The roof is made from slate from Monson, Maine.