On the south the Ninth Ward is bounded by the Mississippi River. On the western or "up river" side, the Ninth Ward is bounded by (going from the Mississippi River north to Lake Pontchartrain) Franklin Avenue, then Almonaster Avenue, then People's Avenue. From the north end of People's Avenue the boundary continues on a straight line north to Lake Pontchartrain; this line is the boundary between the Ninth and the city's Eighth Ward. Lake Ponchartrain forms the north and northeastern end of the ward. Saint Bernard Parish is the boundary to the southeast, Lake Bourne further southeast and east, and the end of Orleans Parish to the east at The Rigolets.
Notable landmarks in this region include the Lakefront Airport, the Industrial Canal, the Doullut Steamboat Houses and Bally's Casino. Some of these landmarks and the region containing them were given a great deal of exposure by the Hot Boys music video "We On Fire", which was partly filmed there. Since then, it has become commonplace for many artists to mention the Ninth Ward in their songs.
While there is substantial overlap, the 9th Ward should not be confused with city planning designation of the ninth planning district of New Orleans. The 9th Ward includes land in planning districts 7, 8, 10, and 11 (not to be confused with the 7th, 8th, 10th, and 11th wards .) 
Among the famous past and present residents of the 9th Ward are Fats Domino, rapper Brian "Baby" Williams, former Washington Husky and NBA basketball player Eldridge Recasner, and Magic—"Mr. Ninth Ward". The area has also produced well known figures like NFL star Marshall Faulk, author Kalamu ya Salaam, trumpeter Kermit Ruffins, and the prominent Baptiste musical family.
The Ninth Ward can broadly be divided into three sections, from where the ward is divided from north to south by the Industrial Canal, and where the area east of the Industrial Canal is divided east to west by the Gulf Intracoastal Waterway/Mississippi River Gulf Outlet.
The portion of the Ninth Ward along the riverfront between Faubourg Marigny and the Industrial Canal is known as Bywater.
Further back are the St. Claude and Florida area neighborhoods, then the Desire neighborhood. This part of the Ward containts two of the Housing Projects of New Orleans. The Desire neighborhood was home to the large Desire Projects, until they were demolished concurrent with HOPE VI policy. Just across Florida avenue from that is the Florida Projects. Nearby was the Agriculture Street Landfill, an old city dump that was covered over and made into a neighborhood of low income housing, then became a Superfund toxic cleanup site.
Other neighborhoods to the West of the Canal include Gentilly Woods, and Pontchartrain Park. Southern University at New Orleans and New Orleans Baptist Theological Seminary is in the neighborhood of Gentilly.
On Friday, January 06, 2006, the governing board for New Orleans public schools approved the sale of eight acres of surplus property in the Upper 9th Ward to the New Orleans Area Habitat for Humanity. Habitat for Humanity is working with Harry Connick Jr. and Branford Marsalis on a Musicians' Village. The Musicians' Village will include Habitat-constructed homes, with a Ellis Marsalis Center for Music, as the centerpiece of the area. The Habitat-built homes will provide musicians of modest means the opportunity to buy decent, affordable housing.
The area to the east of the Industrial Canal and north of the Mississippi River Gulf Outlet is known as "Eastern New Orleans". It is also often called "New Orleans East", although this term is sometimes confined to a smaller section of this area. Neighborhoods to the east of the canal include Lake Kenilworth, Pines Village, Lake Forest East, Lake Forest West, Edgelake, Littlewoods, Plum Orchard, Bonita Park, Donna Villa, Camelot, and Village de L'Est, known for its Vietnamese community. Landmarks in this part of the city's 9th Ward include Lakefront Airport, Joe W. Brown Park, NASA's Michoud Assembly Facility, and the closed Six Flags New Orleans amusement park.
Further east in the Ward, the far eastern portion has little urban development. It includes the Bayou Sauvage National Wildlife Refuge, Chef Menteur Pass, and scattered areas of essentially rural character despite being within the city limits, like Venetian Isles, Irish Bayou and Lake Saint Catherine, and historic Fort Pike on the Rigolets.
The area along the river front was developed first, at the start of the 19th century, followed by the natural high land along Gentilly Ridge.
The designation of this area as the "9th Ward" dates from 1852, when the boundaries of the Wards of New Orleans were redrawn as part of the reorganization of the city from three municipalities into one centralized city government.
Along the lakefront were various fishing camps built on piers, the most famous collection being Little Woods. Such camps were common along the lakefront in the 19th and early 20th century, but the collection at Little Woods was the longest lasting concentration, many surviving until Hurricane Georges in 1998.
The area of the 9th Ward on the back side of St. Claude Avenue experienced the city's most significant and longest standing flooding from the New Orleans Hurricane of 1915 due to a break in the protection levee at Florida Avenue. 
The Industrial Canal was dredged through the neighborhood at the start of the 1920s.
Most of the area between Gentilly Ridge and Lake Ponchartrain was swamp, not drained and developed until the mid and late 20th century.
Lincoln Beach was an amusement park along the lakefront for African-Americans during the era of racial segregation. The nearby "Ponchartrain Beach" was the corresponding amusement area for whites.
Parts of the 9th Ward flooded during Hurricane Flossy in 1956, and the Lower 9th Ward experienced catastrophic flooding in Hurricane Betsy in 1965.
The 9th Ward neighborhood was thrust into the nation's spotlight during Hurricane Katrina. Much of the 9th Ward on both sides of the Industrial Canal experienced catastrophic flooding in Hurricane Katrina in 2005 (see Effect of Hurricane Katrina on New Orleans). The majority of the damage was caused by storm surge. There were multiple severe levee breaks along both the MRGO and the Industrial Canal.
Eastern New Orleans was flooded from multiple sources. The most severe was due to multiple breaches in the MRGO to the south. Some heavy waves during the storm topped the lake levee to the north, which may have contributed to the flooding in some places. Lakefront Airport, outside the main protection levees, was heavily damaged by surge from Lake Pontchartrain. Some water also overtopped a section of the Industrial Canal levee. Most of Eastern New Orleans experienced flooding, generally all areas except the Gentilly/Chef Menteur Ridge and Michoud areas.
The Upper Ninth was flooded by levee & floodwall failures near the Desire neighborhood, across the Industrial Canal from the junction with the MRGO. Flooding in this part of the ward joined with that of the bulk of the City's east bank to the west, with water flowing in from the London Avenue Canal breaches. The old high ground of the section of Bywater on the river side of Saint Claude Avenue was the only substantial neighborhood to escape significant flooding. A few areas on the very highest part of Gentilly Ridge and along the lakefront fill were also above the floodwaters.
The Lower Ninth Ward flooded most catastrophically, with storm surge coming from the east via flooded Saint Bernard Parish and from the west through two large breaches in the Industrial Canal flood protection system, creating violent currents that not only flooded buildings, but smashed them and displaced them from their foundations. Floodwaters propelled the barge ING 4727 into the neighborhood on the other side of the levee from the Industrial Canal.
During several days of the hurricane aftermath, live television news coverage from reporters and anchors who had little familiarity with New Orleans frequently included misinformation, such as referring to the Lower 9th Ward simply as "the 9th Ward" and misidentifying helicopter shots of the Industrial Canal breech as the 17th Street Canal breech (which was actually at the nearly opposite end of the city.)
The Lower 9th Ward, not yet dry from Katrina, was re-flooded by Hurricane Rita a month later.
During Mardi Gras 2006, the 9th Ward was a popular spot for visitors. The national attention the area received due to the hurricane and the events following the disaster provided Carnival revelers with an additional destination during their celebration. Visitors, however, were not the only ones to venture into the area. Locals flocked to the devastated neighborhoods of the ward as well. Hundreds of people gathered near the Florida housing project in the Ninth Ward on Fat Tuesday. In the quasi-celebratory spirit of a jazz funeral, many residents made their first trip back to take part in a massive block party in their former neighborhood.
Two years after the Katrina levee disaster, reconstruction and recovery continues as a slow struggle. Schools and businesses are gradually reopening. Thousands are still waiting for promised insurance or government money which would enable them to make enough repairs to return to living in their damaged homes. Conditions in neighborhoods vary from the thriving Bywater to the portion of the Lower 9th north of Claiborne Avenue where the number of people back is less than one per city block, most of those living in FEMA trailers; the vast majority of the 9th Ward being about halfway between these extremes.