thumb|right|[[All Saints Day in New Orleans – Decorating the Tombs in One of the City Cemeteries, an 1885 engraving]]
Saint Louis Cemetery (, ) is the name of three Catholic cemeteries in New Orleans, Louisiana. Most of the graves are above-ground vaults constructed in the 18th and 19th centuries.
Cemeteries No. 1 and No. 2 are included on the National Register of Historic Places and the Louisiana African American Heritage Trail.
Saint Louis No. 1
thumb|Vaults in Saint Louis No. 1
St. Louis Cemetery No. 1 is the oldest and among the most prominent cemeteries in New Orleans. It was opened in 1789, replacing the city's older St. Peter Cemetery (; no longer in existence) as the main burial ground when the city was redesigned after a fire in 1788.
It is 8 blocks from the Mississippi River, on the north side of Basin Street, one block beyond the inland border of the French Quarter. It borders the former Iberville Projects. It has been in continuous use since its foundation. The nonprofit group Save Our Cemeteries and commercial businesses offer tours for a fee.
Notable New Orleanians buried in St. Louis No. 1 include Etienne de Boré, a wealthy pioneer of the sugar industry and the first mayor of New Orleans; Homer Plessy, the plaintiff from the landmark 1896 Plessy v. Ferguson Supreme Court decision on civil rights. Ernest N. "Dutch" Morial, the first African-American mayor of New Orleans was interred there in 1989. Subsequently, Morial's family built a new family tomb at St. Louis Cemetery No. 3, and Morial's body was reinterred there in late 2014. Notable creole author and educator Alexander Dimitry is buried at
Saint Louis Cemetery Number One. Most of the Dimitry family is interred there including; Andrea Dimitry and his wife Marianne Celeste Dragon. Marianne Céleste Dragon was the subject of a famous portrait painted by José Salazar.
The cemetery inspired an Alkemia Perfumes' scent of the same name, which is described as "An atmospheric brooding of Spanish moss, crumbling stone, old cement, red clay brick, and graveyard dirt."
The renowned Voodoo priestess Marie Laveau is believed to be interred in the Glapion family crypt. Other notable New Orleanians here include Bernard de Marigny, the French-Creole aristocrat and politician who founded both the Faubourg Marigny and Mandeville, Louisiana; Barthelemy Lafon, the architect and surveyor who allegedly became one of Jean Lafitte's pirates; and Paul Morphy, one of the earliest world champions of chess. Delphine LaLaurie, the notoriously cruel slave owner, is also believed to lie in rest here. Architect and engineer Benjamin Latrobe was buried at St. Louis No. 1 after dying from yellow fever in 1820, while doing engineering for the New Orleans water works. In 2010, actor Nicolas Cage purchased a pyramid-shaped tomb to be his future final resting place.
The cemetery spans just one square block but is the resting place of many thousands. A Protestant section (generally not vaulted) lies in the northwest section.
Effective March 1, 2015, the Roman Catholic Archdiocese of New Orleans, which owns and manages this cemetery, has closed it to the general public, ostensibly because of the rise in vandalism there. However, in a controversial move, the diocese is now charging tour companies for access ($4,500 per year, or lesser amounts for short periods). Families who own tombs can apply for a pass to visit.
Saint Louis No. 2
thumb|left|A view between the vaults at cemetery 3