The infected mosquitoes were found in the New Dorp Beach and Bulls Head neighborhoods in the borough, the Health Department said in a press release Tuesday.
The Health Department has increased surveillance and will set up more traps and treat catch basins with pesticides in the neighborhoods where the infected insects were found.
There have been no human cases detected this season, health officials said.
"West Nile Virus has been detected on Staten Island, but simple precautions can help protect you and your family," Thomas Farley, the city's health commissioner, said in a statement. "Wear mosquito repellent when you’re outdoors, and cover your arms and legs if you’re outside at dawn or dusk."
West Nile virus can cause flu-like symptoms including headaches, fever and fatigue. Not everyone who is infected with the virus becomes ill, and people over 50 have a greater risk of contracting the virus.
The detection of West Nile virus comes a day after the city performed its annual spraying for mosquitoes.