On February 21, 1971, Louisiana's only recorded F5 tornado struck Delhi. It took forty-six lives and was the deadliest F5 tornado to hit the United States since the Jackson, Mississippi, Candlestick Park Tornado five years earlier in 1966.
According to the United States Census Bureau, the town has a total area of 2.6 square miles (6.7 km²), of which, 2.5 square miles (6.5 km²) of it is land and 0.1 square miles (0.2 km²) of it (2.33%) is water.
The town's relatively high elevation of 89 ft spared it from the brunt of the massive 1927 Mississippi River flood that destroyed most of the surrounding Mississippi River Delta area.
The newly constructed Poverty Point Reservoir, which hosts the acclaimed Black Bear Golf Club, is located just north of the town on Louisiana Highway 17 near Warden, La.
There were 1,129 households out of which 32.4% had children under the age of 18 living with them, 41.5% were married couples living together, 24.5% had a female householder with no husband present, and 30.2% were non-families. 27.3% of all households were made up of individuals and 15.7% had someone living alone who was 65 years of age or older. The average household size was 2.54 and the average family size was 3.10.
In the town the population was spread out with 26.7% under the age of 18, 10.2% from 18 to 24, 25.9% from 25 to 44, 18.4% from 45 to 64, and 18.9% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 80.8 males. For every 100 females age 18 and over, there were 76.0 males.
The median income for a household in the town was $21,763, and the median income for a family was $25,651. Males had a median income of $25,054 versus $12,837 for females. The per capita income for the town was $11,161. About 26.2% of families and 31.6% of the population were below the poverty line, including 45.7% of those under age 18 and 21.8% of those age 65 or over.