Gasport is east of the City of Lockport.
According to the United States Census Bureau, the village has a total area of 2.9 square miles (7.6 km²), of which, 2.9 square miles (7.4 km²) of it is land and 0.1 square miles (0.2 km²) of it (2.05%) is water.
The hamlet of Gasport is located on New York State Route 31 (Rochester Road) and the Erie Canal.
There were 456 households out of which 30.7% had children under the age of 18 living with them, 57.9% were married couples living together, 9.2% had a female householder with no husband present, and 30.9% were non-families. 25.0% of all households were made up of individuals and 9.6% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 3.04.
In the settlement the population was spread out with 23.0% under the age of 18, 6.9% from 18 to 24, 27.8% from 25 to 44, 23.7% from 45 to 64, and 18.6% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 92.6 males. For every 100 females age 18 and over, there were 90.3 males.
The median income for a household in the community was $39,306, and the median income for a family was $45,313. Males had a median income of $34,167 versus $27,143 for females. The per capita income for the CDP was $17,882. About 2.2% of families and 6.4% of the population were below the poverty line, including 4.0% of those under age 18 and none of those age 65 or over.